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Conversion Units Source File

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foo(x)  [1; kg]  kg m x /hour ; 34 hour / day kg foo

# From: lrclause@shasta.cs.uiuc.edu 
#
# Danish units

#tomme     26.1545 mm
#tommer    tomme       # Plural form
#fod       12 tomme
#alen      2 fod
#danishmil 7.5325 km
#danskmil  danishmil   # Danish form

#tøndeland 5516.23 m^2 # The amount of land that can be sown with one 
#                      # barrel of seed
#tønderland tøndeland  # Plural form

#pot       .9661 l
#kvint     5.0 g
#pund      0.5 kg



#
# wind chill index (WCI) a measurement of the combined cooling effect of low
#      air temperature and wind on the human body. The index was first defined
#      by the American Antarctic explorer Paul Siple in 1939. As currently used
#      by U.S. meteorologists, the wind chill index is computed from the
#      temperature T (in °F) and wind speed V (in mi/hr) using the formula: WCI
#      = 0.0817(3.71 sqrt(V) + 5.81 - 0.25V)(T - 91.4) + 91.4.  The metric
#      equivalent, for T in °C and V in km/hr, is: WCI = 0.045(5.27 sqrt(V) +
#      10.45 - 0.28V)(T - 33) + 33.  For very low wind speeds, below 4 mi/hr or
#      6 km/hr, the WCI is actually higher than the air temperature, but for
#      higher wind speeds it is lower than the air temperature.
# 
# heat index (HI or HX) a measure of the combined effect of heat and
#      humidity on the human body. U.S. meteorologists compute the index
#      from the temperature T (in °F) and the relative humidity H (as a
#      fraction; that is, H = 0.65 if the relative humidity is 65%). The
#      formula used is HI = -42.379 + 2.04901523 T + 1014.333127 H -
#      22.475541 TH - .00683783 T2 - 548.1717 H2 + 0.122874 T2H + 8.5282
#      TH2 - 0.0199 T2H2.
# 

##########################
##########################
#### Working area ########
##########################
##########################

# These definitions are here for testing of the error checking facilities
# of the units program.  All of them are somehow bogus.  

# ev100n(x) 2^x / (m2/cd); log2(ev100 m^2/cd)
# bogusunit 1
# bogusunit(x) x+1
# foo meter**
# baz bleganarf
# wronginv(x) 2 x ; 2 x
# boo(x) x+1
# bug(x) boo(x)+x
# bbb(x) boo(12)
# test(x)  x^2 ; \
#          sqrt(x)
# recur(x) [1]  1+recur(x)
# fezle[kg] 3 4 4 5 5 4 6 3 
# foobiz(x) x x ) ; 3
# testa- (3/4)
# testb- (3/4)/(3/4)
# testc- m/kg/hr
# testt(x) [kg;m] x^2-3 ; sqrt(testt+3)
# 
# 


#
#
# Sugar information
# from Food Science by Norman Potter
#
# boiling pt = 1000+100 (0.52) / W (s/M)  (boiling pt elevation as in books)
#
# 1000 (.512) x / (100-x) 342.3 
#

# Degrees brix measures sugar concentration by weigh as a percentage, so a
# solution that is 3 degrees brix is 3% sugar by weight.  This unit was named
# after Adolf Brix who invented a hydrometer that read this percentage
# directly.  This table converts brix to density at 20 degrees Celsius.  

brix[g/cm^3]  \
   0.0 0.9982,    0.5 1.0002,    1.0 1.0021 \
   1.5 1.0040,    2.0 1.0060,    2.5 1.0079 \
   3.0 1.0099,    3.5 1.0119,    4.0 1.0139 \
   5.0 1.0178,    5.5 1.0198,    6.0 1.0218 \
   6.5 1.0238,    7.0 1.0259,    7.5 1.0279 \
   8.0 1.0299,    8.5 1.0320,    9.0 1.0340 \
   9.5 1.0361,   10.0 1.0381,   11.0 1.0423 \
  12.0 1.0465,   13.0 1.0507,   14.0 1.0549 \
  15.0 1.0592,   16.0 1.0635,   17.0 1.0678 \
  18.0 1.0722,   19.0 1.0766,   20.0 1.0810 \
  22.0 1.0899,   24.0 1.0990,   26.0 1.1082 \
  28.0 1.1175,   30.0 1.1270,   32.0 1.1366 \
  34.0 1.1464,   36.0 1.1562,   38.0 1.1663 \
  40.0 1.1765,   42.0 1.1868,   44.0 1.1972 \
  46.0 1.2079,   48.0 1.2186,   50.0 1.2295 \
  52.0 1.2406,   54.0 1.2518,   56.0 1.2632 \
  58.0 1.2747,   60.0 1.2864,   62.0 1.2983 \
  64.0 1.3103,   66.0 1.3224,   68.0 1.3348 \
  70.0 1.3472,   72.0 1.3599,   74.0 1.3726 \
  76.0 1.3855,   78.0 1.3986,   80.0 1.4117 \
  82.0 1.4250,   84.0 1.4383    

#
#
#Boiling points of sugar syrups
#
#conc tempC
#
#30   100
#40   101
#50   102
#60   103
#70   106
#80   112
#90   123
#95   140
#97   151
#98.2  160
#99.5  166
#99.6  171
#

# The boiling point elevation formula is valid for ideal solutions, i.e.,
# solutions in which the ideal laws hold. In case of boiling point
# elevation, the book is referring to what is called the colligative
# effect, in which the basic effect is the reduction in the mole fraction
# of water. The boiling point of the solution should be linear in the mole
# fraction of water. The higher the molecular weight of the solute, the
# more in terms of weight concentration it takes to affect the boiling
# point.
# 
# As the concentration gets higher, the solutes begin to interact with
# each other. Sometimes the interaction is positive, sometimes negative.
# The result is that the ideal laws, which ignore these interactions, no
# longer hold. The boiling point become nonlinear in mole fraction.
# Unfortunately, science hasn't progressed far enough to enable
# calculation from first principles the magnitude of this nonideality.
# Thus, tables!
# 
# It is difficult to predict where on the concentration scale nonideal
# behavior can be detected. However, consider the molar concentration of a
# sucrose solution. The molecular weight of sucrose is 342 and that of
# water 18.
# 
# wt% sucrose     mole fraction of sucrose
#    10%                  .006
#    20%                  .013
#    30%                  .022
#    40%                  .034
#    50%                  .050
#    60%                  .073
#    70%                  .109
# 
# Even at 50% weight concentration, only one of 20 molecules is sucrose.
# >From this point of view, the solution isn't as concentrated as you
# think!
# 
# According to your data, the boiling point starts to deviate seriously
# from the calculation at 70%. We can see that when 1 of 10 molecules is
# sucrose, interactions become significant. 
# 
# I hope that this way of looking at solutions helps your perspective.
# 
# Guy Bradley 
# 


#################################
#################################
#################################
## Permanent stuff after this  ##
#################################
#################################
#################################


#
# This file is the units database for use with GNU units, a units conversion
# program by Adrian Mariano adrian@cam.cornell.edu
#
# 12 February 2000 Version 1.27
#
# Copyright (C) 1996, 1997, 1998, 1999, 2000  Free Software Foundation, Inc
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
############################################################################
#
# Improvements and corrections are welcome.
#
# Most units data was drawn from
#            1. NIST Special Publication 811, 1995 Edition
#            2. CRC Handbook of Chemistry and Physics 70th edition
#            3. Oxford English Dictionary
#            4. Websters New Universal Unabridged Dictionary
#            5. Units of Measure by Stephen Dresner
#            6. A Dictionary of English Weights and Measures by Ronald Zupko
#            7. British Weights and Measures by Ronald Zupko
#            8. Realm of Measure by Isaac Asimov
#            9. United States standards of weights and measures, their
#                   creation and creators by Arthur H. Frazier.
#           10. French weights and measures before the Revolution: a
#                   dictionary of provincial and local units by Ronald Zupko
#           11. Weights and Measures: their ancient origins and their
#                   development in Great Britain up to AD 1855 by FG Skinner
#           12. The World of Measurements by H. Arthur Klein
#           13. For Good Measure by William Johnstone
#           14. NTC's Encyclopedia of International Weights and Measures 
#                   by William Johnstone
#           15. Sizes by John Lord
#           16. Sizesaurus by Stephen Strauss
#           17. CODATA Recommended Values of Physical Constants available at
#                   http://physics.nist.gov/cuu/Constants/index.html
#           18. How Many?  A Dictionary of Units of Measurement.  Available at
#                   http://www.unc.edu/~rowlett/units/index.html
#
# Thanks to Jeff Conrad for assistance in ferreting out unit definitions.
#
###########################################################################
#
# If units you use are missing or defined incorrectly, please contact me.
#
# If you know anything about the use of or the reason for these units
# please contact me.  These appeared in the original unix data file
# but don't seem to appear anywhere else (they are not defined below):
#
#    bottommeasure        1|40 in
#    imaginarycubicfoot   1.4 ft^3
#    sigma                microsec
#
###########################################################################

###########################################################################
#                                                                         #
# Primitive units.  Any unit defined to contain a '!' character is a      #
# primitive unit which will not be reduced any further.  All units should #
# reduce to primitive units.                                              #
#                                                                         #
###########################################################################

#
# SI units
#

kg        !      # Mass of the international prototype
kilogram  kg

s         !      # Duration of 9192631770 periods of the radiation
second    s      #   corresponding to the transition between the two hyperfine
                 #   levels of the ground state of the cesium-133 atom

m         !      # Length of the path traveled by light in a vacuum
meter     m      #   during 1|299792458 seconds.  Originally meant to be
                 #   1e-7 of the length along a meridian from the equator
                 #   to a pole.

A         !      # The current which produces a force of 2e-7 N/m between two
ampere    A      #   infinitely long wires that are 1 meter apart
amp       ampere

cd        !      # Luminous intensity in a given direction of a source which
candela   cd     #   emits monochromatic radiation at 540e9 Hz with radiant
                 #   intensity 1|683 W/steradian.  (This differs from radiant
                 #   intensity (W/sr) in that it is adjusted for human
                 #   perceptual dependence on wavelength.  The frequency of
                 #   540e9 Hz (yellow) is where human perception is most
                 #   efficient.)

mol       !      # The amount of substance of a system which contains as many
mole      mol    #   elementary entities as there are atoms in 0.012 kg of
                 #   carbon 12.  The elementary entities must be specified and
                 #   may be atoms, molecules, ions, electrons, or other
                 #   particles or groups of particles.  It is understood that
                 #   unbound atoms of carbon 12, at rest and in the ground
                 #   state, are referred to.

K         !      # 1|273.16 of the thermodynamic temperature of the triple
kelvin    K      #   point of water

#
# The radian and steradian are defined to be unitless.  They are included
# as primitive units here because, for the most part, it is less confusing
# if they are irreducible than if they reduce to 1.
#

radian    !      # The angle subtended at the center of a circle by an arc
                 #   equal in length to the radius of the circle

sr        !      # Solid angle which cuts off an area of the surface of
steradian sr     #   the sphere equal to that of a square with sides of
                 #   length equal to the radius of the sphere

#
# Some primitive non-SI units
#

dollar    !      # The US dollar is chosen arbitrarily to be the primitive
$         dollar #   unit of money.

bit       !      # Basic unit of information (entropy).  The entropy in bits
                 #   of a random variable over a finite alphabet is defined
                 #   to be the sum of -p(i)*log2(p(i)) over the alphabet where
                 #   p(i) is the probability that the random variable takes
                 #   on the value i.

###########################################################################
#                                                                         #
# Prefixes (longer names must come first)                                 #
#                                                                         #
###########################################################################

yotta-                  1e24     # Greek or Latin octo, "eight"
zetta-                  1e21     # Latin septem, "seven"
exa-                    1e18     # Greek hex, "six"
peta-                   1e15     # Greek pente, "five"
tera-                   1e12     # Greek teras, "monster"
giga-                   1e9      # Greek gigas, "giant"
mega-                   1e6      # Greek megas, "large"
myria-                  1e4      # Not an official SI prefix
kilo-                   1e3      # Greek chilioi, "thousand"
hecto-                  1e2      # Greek hekaton, "hundred"
deca-                   1e1      # Greek deka, "ten"
deka-                   deca
deci-                   1e-1     # Latin decimus, "tenth"
centi-                  1e-2     # Latin centum, "hundred"
milli-                  1e-3     # Latin mille, "thousand"
micro-                  1e-6     # Latin micro or Greek mikros, "small"
nano-                   1e-9     # Latin nanus or Greek nanos, "dwarf"
pico-                   1e-12    # Spanish pico, "a bit"
femto-                  1e-15    # Danish-Norwegian femten, "fifteen"
atto-                   1e-18    # Danish-Norwegian atten, "eighteen"
zepto-                  1e-21    # Latin septem, "seven"
yocto-                  1e-24    # Greek or Latin octo, "eight"

quarter-                1|4
semi-                   0.5
demi-                   0.5
hemi-                   0.5
half-                   0.5
double-                 2
triple-                 3
treble-                 3

kibi-                   2^10     # In response to the convention of illegally
mebi-                   2^20     # and confusingly using metric prefixes for
gibi-			2^30     # powers of two, the International 
tebi-			2^40     # Electrotechnical Commission aproved these
pebi-			2^50     # binary prefixes for use in 1998.  If you
exbi-			2^60     # want to refer to "megabytes" using the 
Ki-                     kibi     # binary definition, use these prefixes. 
Mi-			mebi
Gi-			gibi
Ti-			tebi
Pi-			pebi
Ei-			exbi

Y-                      yotta
Z-                      zetta
E-                      exa
P-                      peta
T-                      tera
G-                      giga
M-                      mega
k-                      kilo
h-                      hecto
da-                     deka
d-                      deci
c-                      centi
m-                      milli
n-                      nano
p-                      pico
f-                      femto
a-                      atto
z-                      zepto
y-                      yocto

#
# Names of some numbers
#

one                     1
two                     2
double                  2
couple                  2
three                   3
triple                  3
four                    4
quadruple               4
five                    5
quintuple               5
six                     6
seven                   7
eight                   8
nine                    9
ten                     10
twenty                  20
thirty                  30
forty                   40
fifty                   50
sixty                   60
seventy                 70
eighty                  80
ninety                  90
hundred                 100
thousand                1000
million                 1e6

# These number terms were described by N. Chuquet and De la Roche in the 16th
# century as being successive powers of a million.  These definitions are still
# used in most European countries.  The current US definitions for these
# numbers arose in the 17th century and don't make nearly as much sense.  These
# numbers are listed in the CRC Concise Encyclopedia of Mathematics by Eric
# W. Weisstein.

billion                 1e9
trillion                1e12
quadrillion             1e15
quintillion             1e18
sextillion              1e21
septillion              1e24
octillion               1e27
nonillion               1e30
noventillion            nonillion
decillion               1e33
undecillion             1e36
duodecillion            1e39
tredecillion            1e42
quattuordecillion       1e45
quindecillion           1e48
sexdecillion            1e51
septendecillion         1e54
octodecillion           1e57
novemdecillion          1e60
vigintillion            1e63
centillion              1e303

googol                  1e100

brbillion               million^2
brtrillion              million^3
brquadrillion           million^4
brquintillion           million^5
brsextillion            million^6
brseptillion            million^7
broctillion             million^8
brnonillion             million^9
brnoventillion          brnonillion
brdecillion             million^10
brundecillion           million^11
brduodecillion          million^12
brtredecillion          million^13
brquattuordecillion     million^14
brquindecillion         million^15
brsexdecillion          million^16
brseptdecillion         million^17
broctodecillion         million^18
brnovemdecillion        million^19
brvigintillion          million^20

# These numbers fill the gaps left by the European system above.

milliard                1000 million
billiard                1000 million^2
trilliard               1000 million^3
quadrilliard            1000 million^4
quintilliard            1000 million^5
sextilliard             1000 million^6
septilliard             1000 million^7
octilliard              1000 million^8
nonilliard              1000 million^9
noventilliard           nonilliard
decilliard              1000 million^10

# For consistency 

brmilliard              milliard
brbilliard              billiard
brtrilliard             trilliard
brquadrilliard          quadrilliard
brquintilliard          quintilliard
brsextilliard           sextilliard
brseptilliard           septilliard
broctilliard            octilliard
brnonilliard            nonilliard
brnoventilliard         noventilliard
brdecilliard            decilliard

# The British Centillion would be 1e600.  The googolplex is another 
# familiar large number equal to 10^googol.  These numbers give overflows.


#############################################################################
#                                                                           #
# Derived units which can be reduced to the primitive units                 #
#                                                                           #
#############################################################################

#
# Named SI derived units (officially accepted)
#

newton                  kg m / s^2   # force
N                       newton
pascal                  N/m^2        # pressure or stress
Pa                      pascal
joule                   N m          # energy
J                       joule
watt                    J/s          # power
W                       watt
coulomb                 A s          # charge
C                       coulomb
volt                    W/A          # potential difference
V                       volt
ohm                     V/A          # electrical resistance
siemens                 A/V          # electrical conductance
S                       siemens
farad                   C/V          # capacitance
F                       farad
weber                   V s          # magnetic flux
Wb                      weber
henry                   Wb/A         # inductance
H                       henry
tesla                   Wb/m^2       # magnetic flux density
T                       tesla
hertz                   /s           # frequency
Hz                      hertz

#
# units derived easily from SI units
#

gram                    millikg
gm                      gram
g                       gram
tonne                   1000 kg
t                       tonne
metricton               tonne
sthene                  tonne m / s^2
funal                   sthene
pieze                   sthene / m^2
quintal                 100 kg
bar                     1e5 Pa     # About 1 atm
vac                     millibar
micron                  micrometer # One millionth of a meter
bicron                  picometer  # One brbillionth of a meter
cc                      cm^3
are                     100 m^2
liter                   1000 cc       # The liter was defined in 1901 as the
oldliter                1.000028 dm^3 # space occupied by 1 kg of pure water at
l                       liter         # the temperature of its maximum density
                                      # under a pressure of 1 atm.  This was
                                      # supposed to be 1000 cubic cm, but it
                                      # was discovered that the original
                                      # measurement was off.  In 1964, the
                                      # liter was redefined to be exactly 1000
                                      # cubic centimeters.
mho                     siemens    # Inverse of ohm, hence ohm spelled backward
galvat                  ampere     # Named after Luigi Galvani
angstrom                1e-10 m    # Convenient for describing molecular sizes
xunit                   1.00202e-13 meter # Used for measuring wavelengths
siegbahn                xunit             # of X-rays.  It is defined to be
                                          # 1|3029.45 of the spacing of calcite
                                          # planes at 18 degC.  It was intended
                                          # to be exactly 1e-13 m, but was
                                          # later found to be off slightly.
fermi                   1e-15 m    # Convenient for describing nuclear sizes
                                   #   Nuclear radius is from 1 to 10 fermis
barn                    1e-28 m^2  # Used to measure cross section for
                                   #   particle physics collision, said to 
                                   #   have originated in the phrase "big as
                                   #   a barn".
shed                    1e-24 barn # Defined to be a smaller companion to the
                                   #   barn, but it's too small to be of
                                   #   much use.
brewster                micron^2/N # measures stress-optical coef
diopter                 /m         # measures reciprocal of lens focal length
fresnel                 1e12 Hz    # occasionally used in spectroscopy
shake                   1e-8 sec
svedberg                1e-13 s    # Used for measuring the sedimentation
                                   # coefficient for centrifuging.
gamma                   microgram
lambda                  microliter
spat                    1e12 m     # Rarely used for astronomical measurements
preece                  1e13 ohm m # resistivity
planck                  J s        # action of one joule over one second
sturgeon                /henry     # magnetic reluctance
daraf                   1/farad    # elastance (farad spelled backwards)
leo                     10 m/s^2
poiseuille              N s / m^2  # viscosity
mayer                   J/g K      # specific heat
mired                   / microK   # reciprocal color temperature.  The name
                                   #   abbreviates micro reciprocal degree.
crocodile               megavolt   # used informally in UK physics labs
metricounce             25 g
mounce                  metricounce
finsenunit              1e5 W/m^2  # Measures intensity of ultraviolet light
                                   # with wavelength 296.7 nm.
fluxunit                1e-26 W/m^2 Hz # Used in radio astronomy to measure
                                       #   the energy incident on the receiving
                                       #   body across a specified frequency
                                       #   bandwidth.  [12]
jansky                  fluxunit   # K. G. Jansky identified radio waves coming
Jy                      jansky     # from outer space in 1931.
pfu                    / cm^2 sr s # particle flux unit -- Used to measure 
                                   #   rate at which particles are received by
                                   #   a spacecraft as particles per solid
                                   #   angle per detector area per second. [18]
katal                   mol/sec    # Measure of the amount of a catalyst.  One
kat                     katal      #   katal of catalyst enables the reaction
                                   #   to consume or produce on mol/sec. 
#
# time
#

sec                     s
minute                  60 s
min                     minute
hour                    60 min
hr                      hour
day                     24 hr
d                       day
da                      day
week                    7 day
wk                      week
sennight                7 day
fortnight               14 day
blink                   1e-5 day   # Actual human blink takes 1|3 second      
ce                      1e-2 day
cron                    1e6 years
watch                   4 hours    # time a sentry stands watch or a ship's
                                   # crew is on duty. 
bell                    1|8 watch  # Bell would be sounded every 30 minutes.



#
# angular measure
#

circle                  2 pi radian
degree                  1|360 circle
arcdeg                  degree
arcmin                  1|60 degree
arcminute               arcmin
'                       arcmin
arcsec                  1|60 arcmin
arcsecond               arcsec
"                       arcsec
''                      "
rightangle              90 degrees
quadrant                1|4 circle
quintant                1|5 circle
sextant                 1|6 circle

sign                    1|12 circle # Angular extent of one sign of the zodiac
turn                    circle
revolution              turn
rev                     turn
pulsatance              radian / sec
gon                     1|100 rightangle  # measure of grade
grade                   gon
centesimalminute        1|100 grade
centesimalsecond        1|100 centesimalminute
milangle                1|6400 circle     # Official NIST definition.
                                          # Another choice is 1e-3 radian.
pointangle              1|32 circle  # Used for reporting compass readings
centrad                 0.01 radian  # Used for angular deviation of light
                                     # through a prism.
mas                     milli-arcsec # Used by astronomers
seclongitude            circle (seconds/day) # Astronomers measure longitude
                                     # (which they call right ascension) in
                                     # time units by dividing the equator into
                                     # 24 hours instead of 360 degrees. 
#
# Some geometric formulas
#

circlearea(r)   [m;m^2] pi r^2 ; sqrt(circlearea/pi)
spherevolume(r) [m;m^3] 4|3 pi r^3 ; cuberoot(spherevolume/4|3 pi)
spherevol(r)    [m;m^3] spherevolume(r) ; ~spherevolume(spherevol)
square(x)               x^2 ; sqrt(square)

#
# Solid angle measure
#

sphere                  4 pi sr
squaredegree            1|180^2 pi^2 sr
squareminute            1|60^2 squaredegree
squaresecond            1|60^2 squareminute
squarearcmin            squareminute
squarearcsec            squaresecond
sphericalrightangle     0.5 pi sr
octant                  0.5 pi sr

#
# Concentration measures
#

percent                 0.01
%                       percent
mill                    0.001     # Originally established by Congress in 1791
                                  # as a unit of money equal to 0.001 dollars,
                                  # it has come to refer to 0.001 in general.
                                  # Used by some towns to set their property
                                  # tax rate, and written with a symbol similar
                                  # to the % symbol but with two 0's in the
                                  # denominator.  [18]
proof                   1|200     # Alcohol content measured by volume at
                                  # 60 degrees Fahrenheit.  This is a USA
                                  # measure.  In Europe proof=percent.
ppm                     1e-6
partspermillion         ppm
ppb                     1e-9
partsperbillion         ppb       # USA billion
ppt                     1e-12
partspertrillion        ppt       # USA trillion
karat                   1|24      # measure of gold purity
caratgold               karat
gammil                  mg/l
basispoint              0.01 %    # Used in finance 
fine                    1|1000    # Measure of gold purity

# The pH scale is used to measure the concentration of hydronium (H30+) ions in
# a solution.  A neutral solution has a pH of 7 as a result of dissociated
# water molecules.  

pH(x) [;mol/liter] 10^(-x) mol/liter ; (-log(pH liters/mol))


#
# Temperature
#
# Two types of units are defined: units for computing temperature differences
# and functions for converting absolute temperatures.  Conversions for
# differences start with "deg" and conversions for absolute temperature start
# with "temp".  
# 

tempF(x) [;K] (x+(-32)) degF + stdtemp ; (tempF+(-stdtemp))/degF + 32

tempC(x) [;K] x K + stdtemp ; (tempC +(-stdtemp))/K  # In 1741 Anders Celsius
tempcelsius(x) [;K] tempC(x); ~tempC(tempcelsius)    # introduced a temperature
degcelsius              K         # scale with water boiling at 0 degrees and
degC                    K         # freezing at 100 degrees at standard
                                  # pressure. After his death the fixed points
                                  # were reversed and the scale was called the
                                  # centigrade scale.  Due to the difficulty of
                                  # accurately measuring the temperature of
                                  # melting ice at standard pressure, the
                                  # centigrade scale was replaced in 1954 by
                                  # the Celsius scale which is defined by
                                  # subtracting 273.15 from the temperature in
                                  # Kelvins.  This definition differed slightly
                                  # from the old centigrade definition, but the
                                  # Kelvin scale depends on the triple point of
                                  # water rather than a melting point, so it
                                  # can be measured accurately.

tempF(x) [;K] (x+(-32)) degF + stdtemp ; (tempF+(-stdtemp))/degF + 32
tempfahrenheit(x) [;K] tempF(x) ; ~tempF(tempfahrenheit)
degfahrenheit           5|9 degC  # Fahrenheit defined his temperature scale
degF                    5|9 degC  # by setting 0 to the coldest temperature
                                  # he could produce in his lab with a salt
                                  # water solution and by setting 96 degrees to
                                  # body heat.  In Fahrenheit's words: 
                                  #
                                  #    Placing the thermometer in a mixture of
                                  #    sal ammoniac or sea salt, ice, and water
                                  #    a point on the scale will be found which
                                  #    is denoted as zero. A second point is
                                  #    obtained if the same mixture is used
                                  #    without salt. Denote this position as
                                  #    30. A third point, designated as 96, is
                                  #    obtained if the thermometer is placed in
                                  #    the mouth so as to acquire the heat of a
                                  #    healthy man."  (D. G. Fahrenheit,
                                  #    Phil. Trans. (London) 33, 78, 1724)

degreesrankine          degF              # The Rankine scale has the 
degrankine              degreesrankine    # Fahrenheit degree, but it's zero
degreerankine           degF              # is at absolute zero.
degR                    degrankine
tempR                   degrankine
temprankine             degrankine

tempreaumur(x) [;K] x degreaumur+stdtemp ; (tempreaumur+(-stdtemp))/degreaumur 
degreaumur              10|8 degC # The Reaumur scale was used in Europe and
                                  # particularly in France.  It is defined
                                  # to be 0 at the freezing point of water
                                  # and 80 at the boiling point.  Reaumur
                                  # apparently selected 80 because it is
                                  # divisible by many numbers.

degK                    K         # "Degrees Kelvin" is forbidden usage.
tempK                   K         # For consistency.  

#
# Physical constants
#

# Basic constants

pi                      3.14159265358979323846
c                       2.99792458e8 m/s # speed of light in vacuum (exact)
light                   c
mu0                     4 pi 1e-7 H/m    # permeability of vacuum (exact)
epsilon0                1/mu0 c^2        # permittivity of vacuum (exact)
energy                  c^2              # convert mass to energy
e                      1.602176462e-19 C # electron charge
h                     6.62606876e-34 J s # Planck constant
hbar                    h / 2 pi
spin                    hbar
G                 6.673e-11 N m^2 / kg^2 # Newtonian gravity const
coulombconst            1/4 pi epsilon0  # listed as "k" sometimes
au                      1.49597871e11 m  # astronomical unit
astronomicalunit        au

# Physico-chemical constants

atomicmassunit          1.66053873e-27 kg# atomic mass unit (defined to be
u                       atomicmassunit   #   1|12 of the mass of carbon 12)
amu                     atomicmassunit
amu_chem                1.66026e-27 kg   # 1|16 of the weighted average mass of
                                         #   the 3 naturally occuring neutral
                                         #   isotopes of oxygen
amu_phys                1.65981e-27 kg   # 1|16 of the mass of a neutral
                                         #   oxygen 16 atom
dalton                  u                # Maybe this should be amu_chem?
avogadro                grams/amu mol    # size of a mole
N_A                     avogadro
gasconstant           8.314472 J / mol K # molar gas constant
R                       gasconstant
boltzmann               R / N_A          # Boltzmann constant
k                       boltzmann
molarvolume         mol R stdtemp / atm  # Volume occupied by one mole of an
                                         #   ideal gas at STP.  
loschmidt     avogadro mol / molarvolume # Molecules per cubic meter of an
                                         #   ideal gas at STP.  Loschmidt did
                                         #   work similar to Avogadro.  
stefanboltzmann pi^2 k^4 / 60 hbar^3 c^2 # The power per area radiated by a 
sigma                   stefanboltzmann  #   blackbody at temperature T is 
                                         #   given by sigma T^4.
wiendisplacement        2.8977686e-3 m K # Wien's Displacement Law gives the
                                         #   frequency at which the the Planck
                                         #   spectrum has maximum intensity.
                                         #   The relation is lambda T = b where
                                         #   lambda is wavelength, T is
                                         #   temperature and b is the Wien
                                         #   displacement.  This relation is
                                         #   used to determine the temperature
                                         #   of stars.  
K_J    483597.9 GHz/V   # Direct measurement of the volt is difficult.  Until
                        #   recently, laboratories kept Weston cadmium cells as
                        #   a reference, but they could drift.  In 1987 the
                        #   CGPM officially recommended the use of the
                        #   Josephson effect as a laboratory representation of
                        #   the volt.  The Josephson effect occurs when two
                        #   superconductors are separated by a thin insulating
                        #   layer.  A "supercurrent" flows across the insulator
                        #   with a frequency that depends on the potential
                        #   applied across the superconductors.  This frequency
                        #   can be very accurately measured.  The Josephson
                        #   constant K_J, which is equal to 2e/h, relates the
                        #   measured frequency to the potential.  The value
                        #   given here is the officially specified value for
                        #   use beginning in 1990.  The 1998 recommended value
                        #   of the constant is 483597.898 GHz/V.
R_K    25812.807 ohm    # Measurement of the ohm also presents difficulties.
                        #   The old approach involved maintaining resistances
                        #   that were subject to drift.  The new standard is
                        #   based on the Hall effect.  When a current carrying
                        #   ribbon is placed in a magnetic field, a potential
                        #   difference develops across the ribbon.  The ratio
                        #   of the potential difference to the current is
                        #   called the Hall resistance.  Klaus von Klitzing
                        #   discovered in 1980 that the Hall resistance varies
                        #   in discrete jumps when the magnetic field is very
                        #   large and the temperature very low.  This enables
                        #   accurate realization of the resistance h/e^2 in the
                        #   lab.  The value given here is the officially
                        #   specified value for use beginning in 1990.

# Various conventional values

gravity                 9.80665 m/s^2    # std acceleration of gravity (exact)
force                   gravity          # use to turn masses into forces
atm                     101325 Pa        # Standard atmospheric pressure
atmosphere              atm
Hg             13.5951 gram force / cm^3 # Standard weight of mercury (exact)
water                   gram force/cm^3  # Standard weight of water (exact)
waterdensity            gram / cm^3      # Density of water 
H2O                     water
wc                      water            # water column
mach                    331.46 m/s       # speed of sound in dry air at STP
standardtemp            273.15 K         # standard temperature
stdtemp                 standardtemp

# Weight of mercury and water at different temperatures using the standard
# force of gravity.

Hg10C         13.5708 force gram / cm^3  # These units, when used to form  
Hg20C         13.5462 force gram / cm^3  # pressure measures, are not accurate
Hg23C         13.5386 force gram / cm^3  # because of considerations of the
Hg30C         13.5217 force gram / cm^3  # revised practical temperature scale.
Hg40C         13.4973 force gram / cm^3
Hg60F         13.5574 force gram / cm^3  
H2O0C         0.99987 force gram / cm^3
H2O5C         0.99999 force gram / cm^3
H2O10C        0.99973 force gram / cm^3
H2O15C        0.99913 force gram / cm^3
H2O18C        0.99862 force gram / cm^3
H2O20C        0.99823 force gram / cm^3
H2O25C        0.99707 force gram / cm^3
H2O50C        0.98807 force gram / cm^3
H2O100C       0.95838 force gram / cm^3

# Atomic constants

Rinfinity               10973731.568 /m  # The wavelengths of a spectral series
R_H                     10967760 /m      #   can be expressed as 
                                         #     1/lambda = R (1/m^2 - 1/n^2).
                                         #   where R is a number that various
                                         #   slightly from element to element.
                                         #   For hydrogen, R_H is the value,
                                         #   and for heavy elements, the value
                                         #   approaches Rinfinity, which can be
                                         #   computed from 
                                         #        m_e c alpha^2 / 2 h 
                                         #   with a loss of 5 digits
                                         #   of precision.  
alpha                   7.297352533e-3   # The fine structure constant was
                                         #   introduced to explain fine
                                         #   structure visible in spectral
                                         #   lines.  It can be computed from
                                         #         mu0 c e^2 / 2 h  
                                         #   with a loss of 3 digits precision
                                         #   and loss of precision in derived
                                         #   values which use alpha.
bohrradius              alpha / 4 pi Rinfinity
prout                   185.5 keV        # nuclear binding energy equal to 1|12
                                         #   binding energy of the deuteron
# Planck constants

planckmass              2.1767e-8 kg     # sqrt(hbar c / G)
m_P                     planckmass
plancktime              hbar / planckmass c^2
t_P                     plancktime
plancklength            plancktime c
l_P                     plancklength

# Masses of elementary particles

electronmass            5.485799110e-4 u
m_e                     electronmass
protonmass              1.00727646688 u
m_p                     protonmass
neutronmass             1.00866491578 u
m_n                     neutronmass
muonmass                0.1134289168 u
m_mu                    muonmass
deuteronmass            2.01355321271 u
m_d                     deuteronmass
alphaparticlemass       4.0015061747 u
m_alpha                 alphaparticlemass

# particle wavelengths: the compton wavelength of a particle is
# defined as h / m c where m is the mass of the particle.

electronwavelength      h / m_e c            
lambda_C                electronwavelength
protonwavelength        h / m_p c
lambda_C,p              protonwavelength
neutronwavelength       h / m_n c
lambda_C,n              neutronwavelength

# Magnetic moments

bohrmagneton            e hbar / 2 electronmass
mu_B                    bohrmagneton
nuclearmagneton         e hbar /  2 protonmass
mu_N                    nuclearmagneton
mu_mu                   4.49044813e-26 J/T  # Muon magnetic moment
mu_p                    1.410606633e-26 J/T # Proton magnetic moment
mu_e                    928.476362e-26 J/T  # Electron magnetic moment
mu_n                    0.96623640e-26 J/T  # Neutron magnetic moment
mu_d                    0.433073457e-26 J/T # Deuteron magnetic moment

#
# Units derived from physical constants
#

kgf                     kg force
technicalatmosphere     kgf / cm^2
at                      technicalatmosphere
hyl                     kgf s^2 / m   # Also gram-force s^2/m according to [15]
mmHg                    mm Hg
torr                    mmHg     # These units, both named after Evangelista
tor                     Pa       # Torricelli, should not be confused.  
                                 # Acording to [15] the torr is actually 
                                 # atm/760 which is slightly different.
inHg                    inch Hg
inH2O                   inch water
mmH2O                   mm water
eV                      e V      # Energy acquired by a particle with charge e
electronvolt            eV       #   when it is accelerated through 1 V
lightyear               c 365.25 d # The 365.25 day year is specified in
                                   # NIST publication 811
lightsecond             c s
lightminute             c min
parsec                  au / tan(arcsec)    # Unit of length equal to distance
pc                      parsec              #   from the sun to a point having
                                            #   heliocentric parallax of 1
                                            #   arcsec (derived from parallax
                                            #   second).  A distant object with
                                            #   paralax theta will be about
                                            #   (arcsec/theta) parsecs from the
                                            #   sun (using the approximation
                                            #   that tan(theta) = theta).  
rydberg                 h c Rinfinity       # Rydberg energy
crith                   0.089885 gram       # The crith is the mass of one
                                            #   liter of hydrogen at standard
                                            #   temperature and pressure.
amagatvolume            molarvolume
amagat                  mol/amagatvolume    # Used to measure gas densities
lorentz                 bohrmagneton / h c  # Used to measure the extent
                                            #   that the frequency of light
                                            #   is shifted by a magnetic field.
cminv                   h c / cm            # Unit of energy used in infrared
invcm                   cminv               #   spectroscopy.  
wavenumber              cminv
kcal_mol                kcal / mol N_A      # kcal/mol is used as a unit of
                                            #   energy by physical chemists.
#
# CGS system based on centimeter, gram and second
#

dyne                    cm gram / s^2   # force
dyn                     dyne
erg                     cm dyne         # energy
poise                   gram / cm s     # viscosity, honors Jean Poiseuille
P                       poise
rhe                     /poise          # reciprocal viscosity
stokes                  cm^2 / s        # kinematic viscosity
St                      stokes
stoke                   stokes
lentor                  stokes          # old name
Gal                     cm / s^2        # acceleration, used in geophysics
galileo                 Gal             # for earth's gravitational field
                                        # (note that "gal" is for gallon
                                        # but "Gal" is the standard symbol
                                        # for the gal which is evidently a
                                        # shortened form of "galileo".)
barye                   dyne/cm^2       # pressure
barad                   barye           # old name
kayser                  1/cm            # Proposed as a unit for wavenumber
balmer                  kayser          # Even less common name than "kayser"
kine                    cm/s            # velocity
bole                    g cm / s        # momentum
pond                    gram force
glug                gram force s^2 / cm # Mass which is accelerated at
                                        #   1 cm/s^2 by 1 gram force
darcy           centipoise cm^2 / s atm # Measures permeability to fluid flow.

                                        #   One darcy is the permeability of a
                                        #   medium that allows a flow of cc/s
                                        #   of a liquid of centipoise viscosity
                                        #   under a pressure gradient of
                                        #   atm/cm.  Named for H. Darcy. 

mohm                    cm / dyn s      # mobile ohm, measure of mechanical
mobileohm               mohm            #   mobility
mechanicalohm           dyn s / cm      # mechanical resistance
acousticalohm           dyn s / cm^5    # ratio of the sound pressure of
                                        #   1 dyn/cm^2 to a source of strength
                                        #   1 cm^3/s
ray                     acousticalohm
rayl                    dyn s / cm^3    # Specific acoustical resistance
eotvos                  1e-9 Gal/cm     # Change in gravitational acceleration
                                        #   over horizontal distance

# Electromagnetic units derived from the abampere

abampere                10 A            # Current which produces a force of
abamp                   abampere        #   2 dyne/cm between two infinitely
aA                      abampere        #   long wires that are 1 cm apart
biot                    aA              # alternative name for abamp
Bi                      biot
abcoulomb               abamp sec
abcoul                  abcoulomb
abfarad                 abampere sec / abvolt
abhenry                 abvolt sec / abamp
abvolt                  dyne cm  / abamp sec
abohm                   abvolt / abamp
abmho                   /abohm
gauss                   abvolt sec / cm^2
Gs                      gauss
maxwell                 abvolt sec      # Also called the "line"
Mx                      maxwell
oersted                 gauss / mu0
Oe                      oersted
gilbert                 gauss cm / mu0
Gb                      gilbert
Gi                      gilbert
unitpole                4 pi maxwell
emu                     erg/gauss  # "electro-magnetic unit", a measure of
                                   # magnetic moment, often used as emu/cm^3
                                   # to specify magnetic moment density.  

# Gaussian system: electromagnetic units derived from statampere.
#
# Note that the Gaussian units are often used in such a way that Coulomb's law
# has the form F= q1 * q2 / r^2.  The constant 1|4*pi*epsilon0 is incorporated
# into the units.  From this, we can get the relation force=charge^2/dist^2.
# This means that the simplification esu^2 = dyne cm^2 can be used to simplify
# units in the Gaussian system, with the curious result that capacitance can be
# measured in cm, resistance in sec/cm, and inductance in sec^2/cm.  These
# units are given the names statfarad, statohm and stathenry below.  

statampere              10 A cm / s c
statamp                 statampere
statvolt                dyne cm / statamp sec
statcoulomb             statamp s
esu                     statcoulomb
statcoul                statcoulomb
statfarad               statamp sec / statvolt
cmcapacitance           statfarad
stathenry               statvolt sec / statamp
statohm                 statvolt / statamp
statmho                 /statohm
statmaxwell             statvolt sec
franklin                statcoulomb
debye                   1e-18 statcoul cm # unit of electrical dipole moment
helmholtz               debye/angstrom^2  # Dipole moment per area
jar                     1000 statfarad    # approx capacitance of Leyden jar

#
# Some historical eletromagnetic units
#

intampere               0.999835 A    # Defined as the current which in one
intamp                  intampere     #   second deposits .001118 gram of
                                      #   silver from an aqueous solution of
                                      #   silver nitrate.
intfarad                0.999505 F
intvolt                 1.00033 V
intohm                  1.000495 ohm  # Defined as the resistance of a
                                      #   uniform column of mercury containing
                                      #   14.4521 gram in a column 1.063 m
                                      #   long and maintained at 0 degC.
daniell                 1.042 V       # Meant to be electromotive force of a
                                      #   Daniell cell, but in error by .04 V
faraday                 N_A e mol     # Charge that must flow to deposit or
faraday_phys            96521.9 C     #   liberate one gram equivalent of any
faraday_chem            96495.7 C     #   element.  (The chemical and physical
                                      #   values are off slightly from what is
                                      #   obtained by multiplying by amu_chem
                                      #   or amu_phys.  These values are from
                                      #   a 1991 NIST publication.)  Note that
                                      #   there is a Faraday constant which is
                                      #   equal to N_A e and hence has units of
                                      #   C/mol.  
kappline                6000 maxwell  # Named by and for Gisbert Kapp
siemensunit             0.9534 ohm    # Resistance of a meter long column of
                                      #   mercury with a 1 mm cross section.

#
# Photometric units
#

candle                  1.02 candela  # Standard unit for luminous intensity
hefnerunit              0.9 candle    #   in use before candela
hefnercandle            hefnerunit    #
violle                  20.17 cd      # luminous intensity of 1 cm^2 of
                                      #   platinum at its temperature of
                                      #   solidification (2045 K)

lumen                   cd sr         # Luminous flux (luminous energy per
lm                      lumen         #    time unit)

talbot                  lumen s       # Luminous energy
lumberg                 talbot

lux                     lm/m^2        # Illuminance or exitance (luminous
lx                      lux           #   flux incident on or coming from
phot                    lumen / cm^2  #   a surface)
ph                      phot          #
footcandle              lumen/ft^2    # Illuminance from a 1 candela source
                                      #    at a distance of one foot
metercandle             lumen/m^2     # Illuminance from a 1 candela source
                                      #    at a distance of one meter

mcs                     metercandle s # luminous energy per area, used to
                                      #    measure photographic exposure

nox                     1e-3 lux      # These two units were proposed for
skot                    1e-3 apostilb # measurements relating to dark adapted
                                      # eyes.
# Luminance measures

nit                     cd/m^2        # Luminance: the intensity per projected
stilb                   cd / cm^2     # area of an extended luminous source.
sb                      stilb         # (nit is from latin nitere = to shine.)

apostilb                cd/pi m^2
asb                     apostilb
blondel                 apostilb      # Named after a French scientist.

# Equivalent luminance measures.  These units are units which measure
# the luminance of a surface with a specified exitance which obeys
# Lambert's law.  (Lambert's law specifies that luminous intensity of
# a perfectly diffuse luminous surface is proportional to the cosine
# of the angle at which you view the luminous surface.)

equivalentlux           cd / pi m^2   # luminance of a 1 lux surface
equivalentphot          cd / pi cm^2  # luminance of a 1 phot surface
lambert                 cd / pi cm^2
footlambert             cd / pi ft^2

# The bril is used to express "brilliance" of a source of light on a
# logarithmic scale to correspond to subjective perception.  An increase of 1
# bril means doubling the luminance.  A luminance of 1 lambert is defined to
# have a brilliance of 1 bril.  

bril(x) [;lambert]  2^(x+-100) lamberts ;log2(bril/lambert)+100

# Some luminance data from the IES Lighting Handbook, 8th ed, 1993

sunlum                  1.6e9 cd/m^2  # at zenith
sunillum                100e3 lux     # clear sky
sunillum_o              10e3 lux      # overcast sky
sunlum_h                6e6 cd/m^2    # value at horizon
skylum                  8000 cd/m^2   # average, clear sky
skylum_o                2000 cd/m^2   # average, overcast sky
moonlum                 2500 cd/m^2

# Photographic Exposure Value
#
# The Additive Photographic EXposure (APEX) system developed in Germany in
# the 1960s was an attempt to simplify exposure determination for people
# who relied on exposure tables rather than exposure meters.  Shortly
# thereafter, nearly all cameras incorporated exposure meters, so the APEX
# system never caught on, but the concept of Exposure Value (EV) given by
# 
#            A^2   LS   ES
#     2^EV = --- = -- = --
#             T    K    C
# 
# Where
#     A = Relative aperture (f-number)
#     T = Shutter time in seconds
#     L = Scene luminance in cd/m2
#     E = Scene illuminance in lux
#     S = Arithmetic ISO film speed
#     K = Reflected-light meter calibration constant
#     C = Incident-light meter calibration constant
# 
# remains in use.  Strictly speaking, an Exposure Value is a combination
# of aperture and shutter time, but it's also commonly used to indicate
# luminance (or illuminance).  Conversion to luminance or illuminance
# units depends on the ISO film speed and the meter calibration constant.
# Common practice is to use an ISO film speed of 100 (because film speeds
# are in even 1/3-step increments, the exact value is 64 * 2^(2|3)).
# Calibration constants vary among camera and meter manufacturers: Canon,
# Nikon, and Sekonic use a value of 12.5 for reflected-light meters, while
# Minolta and Pentax use a value of 14.  Minolta and Sekonic use a value
# of 250 for incident-light meters with flat receptors.

s100                    64 * 2^(2|3) / lx s     # exact speed for ISO 100 film
			 
# Reflected-light meter calibration constant with ISO 100 film

k1250                   12.5 (cd/m2) / lx s     # For Canon, Nikon, and Sekonic
k1400			14   (cd/m2) / lx s     # For Minolta and Pentax

# Incident-light meter calibration constant with ISO 100 film

c250                    250 lx / lx s           # flat-disc receptor

# Exposure value to scene luminance with ISO 100 film

# For Minolta or Pentax
#ev100(x) [;cd/m^2] 2^x k1400 / s100; log2(ev100 s100 / k1400)  
# For Canon, Nikon or Sekonic
ev100(x) [;cd/m^2] 2^x k1250 / s100; log2(ev100 s100 / k1250)  

# Exposure value to scene illuminance with ISO 100 film

iv100(x) [1;lx] 2^x c250 / s100; log2(iv100 s100 / c250)

#
# Astronomical time measurements
#

anomalisticyear         365.2596 days       # The time between successive
                                            #   perihelion passages of the 
                                            #   earth.
siderealyear            365.256360417 day   # The time for the earth to make
                                            #   one revolution around the sun
                                            #   relative to the stars.
tropicalyear            365.242198781 day   # The mean interval between vernal
                                            #   equinoxes.  Differs from the
                                            #   sidereal year by 1 part in
                                            #   26000 due to precession of the
                                            #   earth about its rotational axis
                                            #   combined with precession of the
                                            #   perihelion of the earth's
                                            #   orbit.
gaussianyear            365.2690 days       # The orbital period of a body in
                                            #   circular orbit at a distance of
                                            #   1 au from the sun.  Calculated
                                            #   from Kepler's third law.
elipseyear              346.62 days         # The line of nodes is the
                                            #   intersection of the plane of
                                            #   Earth's orbit around the sun
                                            #   with the plane of the moon's
                                            #   orbit around earth.  Eclipses
                                            #   can only occur when the moon
                                            #   and sun are close to this
                                            #   line.  The line rotates and
                                            #   appearances of the sun on the
                                            #   line of nodes occur every
                                            #   eclipse year.  
saros                   223 synodicmonth    # The earth, moon and sun appear in
                                            #   the same arrangement every
                                            #   saros, so if an eclipse occurs,
                                            #   then one saros later, a similar
                                            #   eclipse will occur.  (The saros
                                            #   is close to 19 eclipse years.)
                                            #   The eclipse will occur about
                                            #   120 degrees west of the
                                            #   preceeding one because the
                                            #   saros is not an even number of
                                            #   days.  After 3 saros, an
                                            #   eclipse will occur at
                                            #   approximately the same place.
siderealday             23.934469444 hour   # The sidereal day is the interval
siderealhour            1|24 siderealday    #   between two successive transits
siderealminute          1|60 siderealhour   #   of a star over the meridian,
siderealsecond          1|60 siderealminute #   or the time required  for the
                                            #   earth to make one rotation
                                            #   relative to the stars.  The
                                            #   more usual solar day is the
                                            #   time required to make a
                                            #   rotation relative to the sun.
                                            #   Because the earth moves in its
                                            #   orbit, it has to turn a bit
                                            #   extra to face the sun again,
                                            #   hence the solar day is slightly
                                            #   longer.
anomalisticmonth        27.55454977 day     # Time from perigee to perigee
nodicalmonth            27.2122199 day      # The nodes are the points where
draconicmonth           nodicalmonth        #   an orbit crosses the ecliptic.
draconiticmonth         nodicalmonth        #   This is the time required to
                                            #   travel from the ascending node
                                            #   to the next ascending node.
siderealmonth           27.321661 day       # Time required for the moon to
                                            #   orbit the earth
lunarmonth              29.5305555 day      # Time between full moons. Full 
synodicmonth            lunarmonth          #   moon occur when the sun and 
lunation                synodicmonth        #   moon are on opposite sides of
lune                    1|30 lunation       #   the earth.  Since the earth
lunour                  1|24 lune           #   moves around the sun, the moon
                                            #   has to revolve a bit farther to
                                            #   get into the full moon
                                            #   configuration.
year                    tropicalyear
yr                      year
month                   1|12 year
mo                      month
lustrum                 5 years             # The Lustrum was a Roman
                                            #   purification ceremony that took
                                            #   place every five years.
                                            #   Classically educated Englishmen
                                            #   used this term. 
decade                  10 years
century                 100 years
millennium              1000 years
millennia               millennium
solaryear               year
lunaryear               12 lunarmonth
calendaryear            365 day
commonyear              365 day
leapyear                366 day
julianyear              365.25 day
gregorianyear           365.2425 day
islamicyear             354 day          # A year of 12 lunar months. They
islamicleapyear         355 day          # began counting on July 16, AD 622
                                         # when Muhammad emigrated to Medina
                                         # (the year of the Hegira).  They need
                                         # 11 leap days in 30 years to stay in
                                         # sync with the lunar year which is a
                                         # bit longer than the 29.5 days of the
                                         # average month.  The months do not
                                         # keep to the same seasons, but
                                         # regress through the seasons every
                                         # 32.5 years.  
islamicmonth            1|12 islamicyear # They have 29 day and 30 day months.

# The Hewbrew year is also based on lunar months, but synchronized to the solar
# calendar.  The months vary irregularly between 29 and 30 days in length, and
# the years likewise vary.  The regular year is 353, 354, or 355 days long.  To
# keep up with the solar calendar, a leap month of 30 days is inserted every
# 3rd, 6th, 8th, 11th, 14th, 17th, and 19th years of a 19 year cycle.  This
# gives leap years that last 383, 384, or 385 days.  


# Sidereal days

mercuryday              58.6462 day
venusday                243.01 day        # retrograde
earthday                siderealday
marsday                 1.02595675 day
jupiterday              0.41354 day
saturnday               0.4375 day
uranusday               0.65 day          # retrograde
neptuneday              0.768 day
plutoday                6.3867 day

# Planetary sidereal years

mercuryyear             86.96 day
venusyear               224.68 day
earthyear               siderealyear
marsyear                686.95 day
jupiteryear             11.862 tropicalyear
saturnyear              29.458 tropicalyear
uranusyear              84.012 tropicalyear
neptuneyear             164.798 tropicalyear
plutoyear               248.5 tropicalyear

#
# Some other astronomical values
#

sunmass                 1.9891e30 kg
sunradius               6.96e8 m

earthmass               5.9742e24 kg
earthradius             6371331.3 m     # mean 
earthradius_polar       6356912.0 m
earthradius_equatorial  6378388.0 m     # Could be wrong? 6378136.3 m better?
landarea                148.847e6 km^2
oceanarea               361.254e6 km^2

moonmass                7.3483e22 kg
moonradius              1738 km         # mean value

sundist                 1.0000010178 au # mean earth-sun distance
moondist                3.844e8 m       # mean earth-moon distance
sundist_near            1.471e11 m      # earth-sun distance at perihelion
sundist_far             1.521e11 m      # earth-sun distance at aphelion

mercurymass             0.33022e24 kg
venusmass               4.8690e24 kg
marsmass                0.64191e24 kg
jupitermass             1898.8e24 kg
saturnmass              568.5e24 kg
uranusmass              86.625e24 kg
neptunemass             102.78e24 kg
plutomass               0.015e24 kg

mercuryradius           2.57 Mm
venusradius             6.3 Mm
marsradius              3.43 Mm
jupiterradius           72 Mm
saturnradius            60.5 Mm
uranusradius            26.7 Mm
neptuneradius           24.9 Mm

moongravity             1.62 m/s^2

#
# The Hartree system of atomic units, derived from fundamental units
# of mass (of electron), action (planck's constant), charge, and
# the coulomb constant.

# Fundamental units

atomicmass              electronmass
atomiccharge            e
atomicaction            hbar

# derived units (Warning: accuracy is lost from deriving them this way)

atomiclength            bohrradius
atomictime              hbar^3/coulombconst^2 atomicmass e^4 # Period of first
                                                             # bohr orbit
atomicvelocity          atomiclength / atomictime
atomicenergy            hbar / atomictime
hartree                 atomicenergy
Hartree                 hartree

#
# These thermal units treat entropy as charge, from [5]
#

thermalcoulomb          J/K        # entropy
thermalampere           W/K        # entropy flow
thermalfarad            J/K^2
thermalohm              K^2/W      # thermal resistance
fourier                 thermalohm
thermalhenry            J K^2/W^2  # thermal inductance
thermalvolt             K          # thermal potential difference


#
# United States units
#

# linear measure

# The US Metric Law of 1866 gave the exact relation 1 meter = 39.37 inches.
# From 1893 until 1959, the foot was exactly 1200|3937 meters.  In 1959
# the definition was changed to bring the US into agreement with other
# countries.  Since then, the foot has been exactly 0.3048 meters.  At the
# same time it was decided that any data expressed in feet derived from
# geodetic surveys within the US would continue to use the old definition.

US                      1200|3937 m/ft   # These four values will convert
US-                     US               #   international measures to
survey-                 US               #   US Survey measures
geodetic-               US
int                     3937|1200 ft/m   # Convert US Survey measures to
int-                    int              #   international measures

inch                    2.54 cm
in                      inch
foot                    12 inch
feet                    foot
ft                      foot
yard                    3 ft
yd                      yard
mile                    5280 ft

line                    1|12 inch  # Also defined as '.1 in' or as '1e-8 Wb'
rod                     5.5 USyard
perch                   rod
furlong                 40 rod           # From "furrow long" 
statutemile             USmile
league                  3 USmile

# surveyor's measure

surveyorschain          66 surveyft
surveyorspole           1|4 surveyorschain
surveyorslink           1|100 surveyorschain
chain                   surveyorschain
surveychain             chain
ch                      chain
link                    surveyorslink
acre                    10 chain^2
intacre                 43560 ft^2   # Acre based on international ft
acrefoot                acre surveyfoot
section                 USmile^2
township                36 section
homestead               160 acre # Area of land granted by the 1862 Homestead
                                 # Act of the United States Congress
gunterschain            surveyorschain

engineerschain          100 ft
engineerslink           1|100 engineerschain
ramsdenschain           engineerschain
ramsdenslink            engineerslink

# nautical measure

fathom                  6 USft   # Originally defined as the distance from
                                 #   fingertip to fingertip with arms fully
                                 #   extended.
nauticalmile            1852 m   # Supposed to be one minute of latitude at
                                 # the equator.  That value is about 1855 m.
                                 # Early estimates of the earth's circumference
                                 # were a bit off.  The value of 1852 m was
                                 # made the international standard in 1929.
                                 # The US did not accept this value until
                                 # 1954.  The UK switched in 1970.

cable                   1|10 nauticalmile
intcable                cable              # international cable
cablelength             cable
UScable                 100 fathom
navycablelength         720 USft
marineleague            3 nauticalmile
geographicalmile        brnauticalmile
knot                    nauticalmile / hr
click                   km

# Avoirdupois weight

pound                   0.45359237 kg   # The one normally used
lb                      pound           # From the latin libra
grain                   1|7000 pound    # The grain is the same in all three
                                        # weight systems.  It was originally
                                        # defined as the weight of a barley
                                        # corn taken from the middle of the
                                        # ear.
ounce                   1|16 pound
oz                      ounce
dram                    1|16 ounce
dr                      dram
hundredweight           100 pounds      # This is the USA hundredweight
cwt                     hundredweight
shorthundredweight      hundredweight
ton                     2000 lb
shortton                ton
quarter                 1|4 ton
shortquarter            1|4 shortton


# Troy Weight.  In 1828 the troy pound was made the first United States
# standard weight.  It was to be used to regulate coinage.

troypound               5760 grain
troyounce               1|12 troypound
ozt                     troyounce
pennyweight             1|20 troyounce  # Abbreviated "d" in reference to a
dwt                     pennyweight     #   Frankish coin called the "denier"
                                        #   minted in the late 700's.  There  
                                        #   were 240 deniers to the pound.
assayton                mg ton / troyounce   # mg / assayton = troyounce / ton

# Some other jewelers units

metriccarat             0.2 gram        # Defined in 1907
metricgrain             50 mg
carat                   metriccarat
ct                      carat
jewelerspoint           1|100 carat
silversmithpoint        1|4000 inch


# Apothecaries' weight

appound                 troypound
apounce                 troyounce
apdram                  1|8 apounce
scruple                 1|3 apdram

# Liquid measure

gallon                  231 in^3
gal                     gallon
quart                   1|4 gallon
qt                      quart
pint                    1|2 qt
pt                      pint
gill                    1|4 pint
fluidounce              1|16 pint
floz                    fluidounce
fluiddram               1|8 floz
fldr                    fluiddram
minim                   1|60 fldr
liquidbarrel            31.5 gallon
petroleumbarrel         42 gallon       # Originated in Pennsylvania oil
barrel                  petroleumbarrel # fields, from the winetierce
bbl                     barrel
hogshead                63 gallon
firkin                  9 gallon

# Dry measures: The Winchester Bushel was defined by William III in 1702 and
# legally adopted in the US in 1836.

bushel                  2150.42 in^3  # Volume of 8 inch cylinder with 18.5
bu                      bushel        # inch diameter (rounded)
peck                    1|4 bushel
pk                      peck
drygallon               1|2 peck
dryquart                1|4 drygallon
drypint                 1|2 dryquart
drybarrel               7056 in^3     # Used in US for fruits, vegetables,
                                      #   and other dry commodities except for
                                      #   cranberries.
cranberrybarrel         5826 in^3     # US cranberry barrel
heapedbushel            1.278 bushel  # Why this particular value?  Often
                                      #   rounded to 1.25 bushels. 

# Grain measures.  The bushel as it is used by farmers in the USA is actually
# a measure of mass which varies for different commodities.  Canada uses the
# same bushel masses for most commodities, but not for oats.

wheatbushel             60 lb
soybeanbushel           60 lb
cornbushel              56 lb
ryebushel               56 lb
barleybushel            48 lb 
oatbushel               32 lb
ricebushel              45 lb
canada_oatbushel        34 lb

# Wine and Spirits measure

pony                    1 floz
jigger                  1.5 floz   # Can vary between 1 and 2 floz
shot                    jigger     # Sometimes 1 floz
eushot                  25 ml      # EU standard spirits measure
fifth                   1|5 gallon
winebottle              750 ml     # US industry standard, 1979
winesplit               1|4 winebottle
wineglass               4 floz
magnum                  1.5 liter  # Standardized in 1979, but given
                                   # as 2 qt in some references
metrictenth             375 ml
metricfifth             750 ml
metricquart             1 liter

# French champagne bottle sizes

split                   200 ml
jeroboam                2 magnum
rehoboam                3 magnum
methuselah              4 magnum
salmanazar              6 magnum
balthazar               8 magnum
nebuchadnezzar          10 magnum

#
# Water is "hard" if it contains various minerals, expecially calcium
# carbonate.  
#

clarkdegree     1|70000       # Content by weigh of calcium carbonate
gpg             grains/gallon # Divide by water's density to convert to
                              #   a dimensionless concentration measure
#
# Shoe measures
#

shoeiron                1|48 inch    # Used to measure leather in soles
shoeounce               1|64 inch    # Used to measure non-sole shoe leather

#
# USA slang units
#

buck                    dollar
fin                     5 dollar
sawbuck                 10 dollar
key                     kg           # usually of marijuana, 60's
lid                     1 oz         # Another 60's weed unit
footballfield           100 yards
marathon                26 miles + 385 yards

#
# British
#

UK                      1200000|3937014 m/ft  # The UK lengths were defined by
british-                UK                    # a bronze bar manufactured in
UK-                     UK                    # 1844.  Measurement of that bar
                                              # revealed the dimensions given
                                              # here.

brnauticalmile          6080 ft               # Used until 1970 when the UK
brknot                  brnauticalmile / hr   # switched to the international
brcable                 1|10 brnauticalmile   # nautical mile.
admiraltymile           brnauticalmile
admiraltyknot           brknot
admiraltycable          brcable
seamile                 6000 ft
shackle                 15 fathoms            # Adopted 1949 by British navy

# British Imperial weight is mostly the same as US weight.  A few extra
# units are added here.

clove                   7 lb
stone                   14 lb
tod                     28 lb
brquartermass           1|4 brhundredweight
brhundredweight         8 stone
longhundredweight       brhundredweight
longton                 20 brhundredweight
brton                   longton
brassayton              mg brton / troyounce

# British Imperial volume measures

brminim                 1|60 brdram
brscruple               1|3 brdram
fluidscruple            brscruple
brdram                  1|8 brfloz
brfloz                  1|20 brpint
brfluidounce            brfloz
brgill                  1|4 brpint
brpint                  1|2 brquart
brquart                 1|4 brgallon
brgallon                4.54609 l      # The British Imperial gallon was
canadiangallon          brgallon       # defined in 1824 to be the volume of
cangallon               brgallon       # water which weighed 10 pounds at 62
                                       # deg F with a pressure of 30 inHg.  In
                                       # 1963 it was defined to be the volume
                                       # occupied by 10 pounds of distilled
                                       # water of density 0.998859 g/ml weighed
                                       # in air of density 0.001217 g/ml
                                       # against weights of density 8.136 g/ml.
                                       # This gives a value of approximately
                                       # 4.5459645 liters, but the old liter
                                       # was in force at this time.  In 1976
                                       # the definition was changed to exactly
                                       # 4.54609 liters using the new
                                       # definition of the liter (1 dm^3).
brpeck                  2 brgallon
brbarrel                36 brgallon    # Used for beer
brbushel                4 brpeck
brheapedbushel          1.278 brbushel
brquarter               8 brbushel
brchaldron              36 brbushel

# Obscure British volume measures.  These units are generally traditional
# measures whose definitions have fluctuated over the years.  Often they
# depended on the quantity being measured.  They are given here in terms of
# British Imperial measures.  For example, the puncheon may have historically
# been defined relative to the wine gallon or beer gallon or ale gallon
# rather than the British Imperial gallon.

bag                     4 brbushel
bucket                  4 brgallon
last                    40 brbushel
noggin                  brgill
pottle                  0.5 brgallon
pin                     4.5 brgallon
puncheon                72 brgallon
seam                    8 brbushel
coomb                   4 brbushel
boll                    6 brbushel   
firlot                  1|4 boll
brfirkin                9 brgallon     # Used for ale and beer
cran                    37.5 brgallon  # measures herring, about 750 fish
brhogshead              63 brgallon
registerton             100 ft^3  # Used for internal capacity of ships
shippington             40 ft^3   # Used for ship's cargo freight or timber
brshippington           42 ft^3   #
freightton            shippington # Both register ton and shipping ton derive
                                  # from the "tun cask" of wine.
displacementton         35 ft^3   # Approximate volume of a longton weight of
                                  # sea water.  Measures water displaced by
                                  # ships.
waterton                224 brgallon
strike                  70.5 l    # 16th century unit, sometimes
                                  #   defined as .5, 2, or 4 bushels
                                  #   depending on the location.  It
                                  #   probably doesn't make a lot of
                                  #   sense to define in terms of imperial
                                  #   bushels.  Zupko gives a value of
                                  #   2 Winchester grain bushels or about
                                  #   70.5 liters.
amber		        4 bushel  # Used for dry and liquid capacity [18]

# obscure British lengths

barleycorn              1|3 UKinch   # Given in Realm of Measure as the
                                     # difference between successive shoe sizes
nail                    1|16 UKyard  # Originally the width of the thumbnail,
                                     #   or 1|16 ft.  This took on the general
                                     #   meaning of 1|16 and settled on the
                                     #   nail of a yard or 1|16 yards as its
                                     #   final value.  [12]
pole                    16.5 UKft
rope                    20 UKft
englishell              45 UKinch
flemishell              27 UKinch
ell                     englishell   # supposed to be measure from elbow to
                                     #   fingertips
span                    9 UKinch     # supposed to be distance from thumb
                                     #   to pinky with full hand extension
goad                    4.5 UKft     # used for cloth, possibly named after the
                                     #   stick used for prodding animals.

# misc obscure British units

rood                    1|4 acre
englishcarat            3.163 grain     # Originally intended to be 4 grain
                                        #   but this value ended up being
                                        #   used in the London diamond market
mancus                  2 oz
mast                    2.5 lb
basebox                 31360 in^2      # Used in metal plating

# alternate spellings

metre                   meter
gramme                  gram
litre                   liter
dioptre                 diopter
aluminium               aluminum
sulphur                 sulfur

#
# Units derived the human body (may not be very accurate)
#

geometricpace           5 ft   # distance between points where the same
                               # foot hits the ground
pace                    2.5 ft # distance between points where alternate
                               # feet touch the ground
USmilitarypace          30 in  # United States official military pace
USdoubletimepace        36 in  # United States official doubletime pace
fingerbreadth           7|8 in # The finger is defined as either the width
fingerlength            4.5 in #   or length of the finger
finger                  fingerbreadth
palmwidth               hand   # The palm is a unit defined as either the width
palmlength              8 in   #   or the length of the hand
hand                    4 inch # width of hand
shaftment               6 inch # Distance from tip of outstretched thumb to the
                               #   opposite side of the palm of the hand.  The
                               #   ending -ment is from the old English word
                               #   for hand. [18]
#
# Cooking measures
#

# US measures

cup                     8 floz
tablespoon              1|16 cup
tbl                     tablespoon
tbsp                    tablespoon
teaspoon                1|3 tbsp
tsp                     teaspoon
saltspoon               1|4 tsp
metriccup               250 ml
stickbutter             1|4 lb            # Butter in the USA is sold in one
                                          # pound packages that contain four
                                          # individually wrapped pieces.  The
                                          # pieces are marked into tablespoons,
                                          # making it possible to measure out
                                          # butter by volume by slicing the
                                          # butter.  

# US can sizes. 

number1can              10 floz
number2can              19 floz
number2.5can            3.5 cups
number3can              4 cups
number5can              7 cups
number10can             105 floz

# British measures

brcup                   1|2 brpint
brteacup                1|3 brpint
brtablespoon            15 ml             # Also 5|8 brfloz, approx 17.7 ml
brteaspoon              1|3 brtablespoon  # Also 1|4 brtablespoon
dessertspoon            2 brteaspoon
brtsp                   brteaspoon
brtbl                   brtablespoon
dsp                     dessertspoon

# Australian

australiatablespoon     20 ml
austbl                  australiatablespoon

# Chinese

catty                   0.5 kg         
oldcatty                4|3 lbs        # Before metric conversion.
tael                    1|16 oldcatty  # Should the tael be defined both ways?
mace			0.1 tael
oldpicul                100 oldcatty
picul                   100 catty      # Chinese usage

# Japanese

japancup                200 ml         

# densities of cooking ingredients from The Cake Bible by Rose Levy Beranbaum
# so you can convert '2 cups sugar' to grams, for example, or in the other
# direction grams could be converted to 'cup flour_scooped'.  

butter                  8 oz/cup
butter_clarified        6.8 oz/cup
cocoa_butter            9 oz/cup
shortening              6.75 oz/cup     # vegetable shortening
oil                     7.5 oz/cup
cakeflour_sifted        3.5 oz/cup      # The density of flour depends on the  
cakeflour_spooned       4 oz/cup        # measuring method.  "Scooped",  or    
cakeflour_scooped       4.5 oz/cup      # "dip and sweep" refers to dipping a  
flour_sifted            4 oz/cup        # measure into a bin, and then sweeping
flour_spooned           4.25 oz/cup     # the excess off the top.  "Spooned"   
flour_scooped           5 oz/cup        # means to lightly spoon into a measure
breadflour_sifted       4.25 oz/cup     # and then sweep the top.  Sifted means
breadflour_spooned      4.5 oz/cup      # sifting the flour directly into a    
breadflour_scooped      5.5 oz/cup      # measure and then sweeping the top.   
cornstarch              120 grams/cup
dutchcocoa_sifted       75 g/cup        # These are for Dutch processed cocoa
dutchcocoa_spooned      92 g/cup
dutchcocoa_scooped      95 g/cup
cocoa_sifted            75 g/cup        # These are for nonalkalized cocoa
cocoa_spooned           82 g/cup
cocoa_scooped           95 g/cup
heavycream              232 g/cup
milk                    242 g/cup
sourcream               242 g/cup
molasses                11.25 oz/cup
cornsyrup               11.5 oz/cup
honey                   11.75 oz/cup
sugar                   200 g/cup
powdered_sugar          4 oz/cup
brownsugar_light        217 g/cup       # packed
brownsugar_dark         239 g/cup

baking_powder           4.6 grams / tsp
salt                    6 g / tsp
koshersalt              2.8 g / tsp     # Diamond Crystal salt, from package
                                        # Note that Morton kosher salt is 
                                        # much denser.  

# Egg weights and volumes for a USA large egg

egg                     50 grams
eggwhite                30 grams
eggyolk                 18.6 grams
eggvolume               3 tablespoons + 1|2 tsp
eggwhitevolume          2 tablespoons
eggyolkvolume           3.5 tsp

#
# Density measures.  Density has traditionally been measured on a variety of
# bizarre nonlinear scales.  
#

# Often used in European recipes to specify the density of a sugar syrup. 
# An entirely different definition is used for densities below 1 g/cm^3. 
# An arbitrary constant appears in the definition.  This value is equal to 145
# in the US, but was according to [], the old scale used in Holland had a value
# of 144, and the new scale or Gerlach scale used 146.78.

baumeconst 145      # US value
baume(d) [1;g/cm^3] (baumeconst/(baumeconst+-d)) g/cm^3 ; \
                    (baume+((-g)/cm^3)) baumeconst / baume

twaddell(x) [1;g/cm^3] (1 + 0.005 x) g / cm^3 ; 200 (twaddell / (g/cm^3) +- 1)

# Density measure invented by the American Petroleum Institute.  Lighter
# petroleum products are more valuable, and they get a higher API degree.
 
apidegree(x) [1;g/cm^3] 141.5 g/cm^3 / (x+131.5) ; \
                        141.5 (g/cm^3) / apidegree + (-131.5)

#
# Units derived from imperial system
#

ouncedal                oz ft / s^2     # force which accelerates an ounce
                                        #    at 1 ft/s^2
poundal                 lb ft / s^2     # same thing for a pound
tondal                  ton ft / s^2    # and for a ton
pdl                     poundal
psi                     pound force / inch^2
psia                    psi             # absolute pressure
tsi                     ton force / inch^2
reyn                    psi sec
slug                    lbf s^2 / ft
slugf                   slug force
slinch                  lbf s^2 / inch  # Mass unit derived from inch second
slinchf                 slinch force    #   pound-force system.  Used in space
                                        #   applications where in/sec^2 was a
                                        #   natural acceleration measure. 
geepound                slug
lbf                     lb force
tonf                    ton force
lbm                     lb
kip                     1000 lbf     # from kilopound
mil                     0.001 inch
thou                    0.001 inch
circularinch            1|4 pi in^2  # area of a one-inch diameter circle
circularmil             1|4 pi mil^2 # area of one-mil diameter circle
cmil                    circularmil
cental                  100 pound
centner                 cental
caliber                 0.01 inch    # for measuring bullets
duty                    ft lbf
celo                    ft / s^2
jerk                    ft / s^3
australiapoint          0.01 inch    # The "point" is used to measure rainfall
                                     #   in Australia
sabin                   ft^2         # Measure of sound absorption equal to the
                                     #   absorbing power of one square foot of
                                     #   a perfectly absorbing material.  The
                                     #   sound absorptivity of an object is the
                                     #   area times a dimensionless
                                     #   absorptivity coefficient.
standardgauge          4 ft + 8.5 in # Standard width between railroad track
flag                   5 ft^2        # Construction term referring to sidewalk.
rollwallpaper          30 ft^2       # Area of roll of wall paper
fillpower              in^3 / ounce  # Density of down at standard pressure.
                                     #   The best down has 750-800 fillpower. 
pinlength              1|16 inch     # A #17 pin is 17/16 in long in the USA.
buttonline             1|40 inch     # The line was used in 19th century USA
                                     #   to measure width of buttons.
scoopnumber            /quart        # Ice cream scoops are labeled with a  
                                     #   number specifying how many scoops  
                                     #   fill a quart.
beespace               1|4 inch      # Bees will fill any space that is smaller
                                     #   than the bee space and leave open
                                     #   spaces that are larger.  The size of
                                     #   the space varies with species.  
diamond                8|5 ft        # Marking on US tape measures that is
                                     #   useful to carpenters who wish to place
                                     #   five studs in an 8 ft distance. 

#
# Other units of work, energy, power, etc
#

# Calories: energy to raise a gram of water one degree celsius

cal_IT                  4.1868 J     # International Table calorie
cal_th                  4.184 J      # Thermochemical calorie
cal_fifteen             4.18580 J    # Energy to go from 14.5 to 15.5 degC
cal_twenty              4.18190 J    # Energy to go from 19.5 to 20.5 degC
cal_mean                4.19002 J    # 1|100 energy to go from 0 to 100 degC
calorie                 cal_IT
cal                     calorie
calorie_IT              cal_IT
thermcalorie            cal_th
calorie_th              thermcalorie
Calorie                 kilocalorie  # the food Calorie
thermie              1e6 cal_fifteen # Heat required to raise the
                                     # temperature of a tonne of
                                     # water from 14.5 to 15.5 degC.

# btu definitions: energy to raise a pound of water 1 degF

btu                     cal lb degF / gram K # international table BTU
britishthermalunit      btu
btu_IT                  btu
btu_th                  cal_th lb degF / gram K
btu_mean                cal_mean lb degF / gram K
quad                    quadrillion btu

ECtherm                 1.05506e8 J    # Exact definition, close to 1e5 btu
UStherm                 1.054804e8 J   # Exact definition
therm                   UStherm
toe                     41.868 GJ      # ton oil equivalent.  Energy released
                                       # by burning one metric ton of oil. [18]
tonscoal                1|2.3 toe      # Energy in metric ton coal from [18].
naturalgas              toe / 1270 m^3 # Energy released from natural gas
			               # from [18].  (At what pressure?)

# Celsius heat unit: energy to raise a pound of water 1 degC

celsiusheatunit         cal lb degC / gram K
chu                     celsiusheatunit

# The horsepower is supposedly the power of one horse pulling.   Obviously
# different people had different horses.

horsepower              550 foot pound force / sec   # Invented by James Watt
hp                      horsepower
metrichorsepower        75 kilogram force meter / sec
electrichorsepower      746 W
boilerhorsepower        9809.50 W
waterhorsepower         746.043 W
brhorsepower            745.70 W
donkeypower             250 W

# Thermal insulance: Thermal conductivity has dimension power per area per
# (temperature difference per length thickness) which comes out to W / K m.  If
# the thickness is fixed, then the conductance will have units of W / K m^2.
# Thermal insulance is the reciprocal.

Rvalue                  degF ft^2 hr / btu
Uvalue                  1/Rvalue
europeanUvalue          watt / m^2 K
RSI                     degC m^2 / W
clo                     0.155 degC m^2 / W # Supposed to be the insulance 
                                           # required to keep a resting person
                                           # comfortable indoors.  The value
                                           # given is from NIST and the CRC,
                                           # but [5] gives a slightly different
                                           # value of 0.875 ft^2 degF hr / btu.
tog                     0.1 degC m^2 / W   # Also used for clothing. 

# Misc other measures


clausius                1e3 cal/K       # A unit of physical entropy
langley                 thermcalorie/cm^2
poncelet                100 kg force m / s
tonrefrigeration        ton 144 btu / lb day # One ton refrigeration is
                                        # the rate of heat extraction required
                                        # turn one ton of water to ice in
                                        # a day.  Ice is defined to have a
                                        # latent heat of 144 btu/lb.
tonref                  tonrefrigeration
refrigeration           tonref / ton
frigorie                1000 cal_fifteen# Used in refrigeration engineering.
tnt                     4.184e9 J/ton   # So you can write tons-tnt, this
                                        # is a defined, not measured, value.
airwatt                 8.5 (ft^3/min) inH2O # Measure of vacuum power as
                                             # pressure times air flow.

#
# Permeability: The permeability or permeance, n, of a substance determines
# how fast vapor flows through the substance.  The formula W = n A dP
# holds where W is the rate of flow (in mass/time), n is the permeability,
# A is the area of the flow path, and dP is the vapor pressure difference.
#

perm_0C                 grain / hr ft^2 inHg
perm_zero               perm_0C
perm_0                  perm_0C
perm                    perm_0C
perm_23C                grain / hr ft^2 in Hg23C
perm_twentythree        perm_23C

#
# Counting measures
#

pair                    2
brace                   2   
nest                    3     # often used for items like bowls that
                              #   nest together 
hattrick                3     # Used in sports, especially cricket and ice
                              #   hockey to report the number of goals. 
dicker                  10
dozen                   12
bakersdozen             13
score                   20
flock                   40
timer                   40
shock                   60
gross                   144
greatgross              12 gross
tithe                   1|10  # From Anglo-Saxon word for tenth

# Paper counting measure

shortquire              24
quire                   25
shortream               480
ream                    500     
perfectream             516
bundle                  2 reams
bale                    5 bundles

#
# Paper measures
#

# USA paper sizes 

lettersize              8.5 inch 11 inch
legalsize               8.5 inch 14 inch
ledgersize              11 inch 17 inch
executivesize           7.25 inch 10.5 inch
Apaper                  8.5 inch 11 inch
Bpaper                  11 inch 17 inch
Cpaper                  17 inch 22 inch
Dpaper                  22 inch 34 inch
Epaper                  34 inch 44 inch

pointthickness          mil

# The metric paper sizes are defined so that if a sheet is cut in half
# along the short direction, the result is two sheets which are
# similar to the original sheet.  This means that for any metric size,
# the long side is close to sqrt(2) times the length of the short
# side.  Each series of sizes is generated by repeated cuts in half, 
# with the values rounded down to the nearest millimeter.  

A0paper                 841 mm 1189 mm   # The basic size in the A series
A1paper                 594 mm  841 mm   # is defined to have an area of 
A2paper                 420 mm  594 mm   # one square meter.
A3paper                 297 mm  420 mm
A4paper                 210 mm  297 mm
A5paper                 148 mm  210 mm
A6paper                 105 mm  148 mm
A7paper                  74 mm  105 mm
A8paper                  52 mm   74 mm
A9paper                  37 mm   52 mm
A10paper                 26 mm   37 mm

B0paper                1000 mm 1414 mm   # The basic B size has an area
B1paper                 707 mm 1000 mm   # of sqrt(2) square meters.  
B2paper                 500 mm  707 mm
B3paper                 353 mm  500 mm
B4paper                 250 mm  353 mm
B5paper                 176 mm  250 mm
B6paper                 125 mm  176 mm
B7paper                  88 mm  125 mm
B8paper                  62 mm   88 mm
B9paper                  44 mm   62 mm
B10paper                 31 mm   44 mm

C0paper                 917 mm 1297 mm   # The basic C size has an area
C1paper                 648 mm  917 mm   # of sqrt(sqrt(2)) square meters.
C2paper                 458 mm  648 mm
C3paper                 324 mm  458 mm   # Intended for envelope sizes
C4paper                 229 mm  324 mm
C5paper                 162 mm  229 mm
C6paper                 114 mm  162 mm
C7paper                  81 mm  114 mm
C8paper                  57 mm   81 mm
C9paper                  40 mm   57 mm
C10paper                 28 mm   40 mm

# gsm (Grams per Square Meter), a sane, metric paper weight measure

gsm                     grams / meter^2

# In the USA, a collection of crazy historical paper measures are used.  Paper
# is measured as a weight of a ream of that particular type of paper.  This is
# sometimes called the "substance" or "basis" (as in "substance 20" paper).
# The standard sheet size or "basis size" varies depending on the type of
# paper.  As a result, 20 pound bond paper and 50 pound text paper are actually
# about the same weight.  The different sheet sizes were historically the most
# convenient for printing or folding in the different applications.  These
# different basis weights are standards maintained by American Society for
# Testing Materials (ASTM) and the American Forest and Paper Association
# (AF&PA).

poundbookpaper          lb / 25 inch 38 inch ream
lbbook                  poundbookpaper
poundtextpaper          poundbookpaper
lbtext                  poundtextpaper
poundoffsetpaper        poundbookpaper    # For offset printing
lboffset                poundoffsetpaper
poundbiblepaper         poundbookpaper    # Designed to be lightweight, thin,
lbbible                 poundbiblepaper   # strong and opaque.
poundtagpaper           lb / 24 inch 36 inch ream 
lbtag                   poundtagpaper
poundbagpaper           poundtagpaper
lbbag                   poundbagpaper
poundnewsprintpaper     poundtagpaper
lbnewsprint             poundnewsprintpaper
poundposterpaper        poundtagpaper
lbposter                poundposterpaper
poundtissuepaper        poundtagpaper
lbtissue                poundtissuepaper
poundwrappingpaper      poundtagpaper
lbwrapping              poundwrappingpaper
poundwaxingpaper        poundtagpaper
lbwaxing                poundwaxingpaper
poundglassinepaper      poundtagpaper
lbglassine              poundglassinepaper
poundcoverpaper         lb / 20 inch 26 inch ream
lbcover                 poundcoverpaper
poundindexpaper         lb / 25.5 inch 30.5 inch ream
lbindex                 poundindexpaper
poundindexbristolpaper  poundindexpaper
lbindexbristol          poundindexpaper
poundbondpaper          lb / 17 inch 22 inch ream  # Bond paper is stiff and
lbbond                  poundbondpaper             # durable for repeated
poundwritingpaper       poundbondpaper             # filing, and it resists
lbwriting               poundwritingpaper          # ink penetration.  
poundledgerpaper        poundbondpaper
lbledger                poundledgerpaper
poundcopypaper          poundbondpaper
lbcopy                  poundcopypaper
poundblottingpaper      lb / 19 inch 24 inch ream
lbblotting              poundblottingpaper
poundblankspaper        lb / 22 inch 28 inch ream
lbblanks                poundblankspaper
poundpostcardpaper      lb / 22.5 inch 28.5 inch ream
lbpostcard              poundpostcardpaper
poundweddingbristol     poundpostcardpaper
lbweddingbristol        poundweddingbristol
poundbristolpaper       poundweddingbristol
lbbristol               poundbristolpaper
poundboxboard           lb / 1000 ft^2
lbboxboard              poundboxboard
poundpaperboard         poundboxboard
lbpaperboard            poundpaperboard

# When paper is marked in units of M, it means the weight of 1000 sheets of the
# given size of paper.  To convert this to paper weight, divide by the size of
# the paper in question.

paperM                  lb / 1000       

#
# Printing
#

fournierpoint           0.1648 inch / 12  # First definition of the printers
                                          # point made by Pierre Fournier who
                                          # defined it in 1737 as 1|12 of a
                                          # cicero which was 0.1648 inches.
olddidotpoint           1|72 frenchinch   # François Ambroise Didot, one of 
                                          # a family of printers, changed
                                          # Fournier's definition around 1770 
                                          # to fit to the French units then in
                                          # use.  
bertholdpoint           1|2660 m          # H. Berthold tried to create a 
                                          # metric version of the didot point
                                          # in 1878.  
INpoint                 0.4 mm            # This point was created by a 
                                          # group directed by Fermin Didot in
                                          # 1881 and is associated with the 
                                          # imprimerie nationale.  It doesn't
                                          # seem to have been used much.
germandidotpoint        0.376065 mm       # Exact definition appears in DIN
                                          # 16507, a German standards document
                                          # of 1954.  Adopted more broadly  in
                                          # 1966 by ???
metricpoint             3|8 mm            # Proposed in 1977 by Eurograf
point                   1|72.27 inch      # The American point was invented
printerspoint           point             # by Nelson Hawks in 1879 and 
                                          # dominates USA publishing.
                                          # It was standardized by the American
                                          # Typefounders Association at the
                                          # value of 0.013837 inches exactly.
                                          # Knuth uses the approximation given
                                          # here (which is very close).  The
                                          # comp.fonts FAQ claims that this
                                          # value is supposed to be 1|12 of a
                                          # pica where 83 picas is equal to 35
                                          # cm.  But this value differs from
                                          # the standard.  
texscaledpoint          1|65536 point     # The TeX typesetting system uses
texsp                   texscaledpoint    # this for all computations.
computerpoint           1|72 inch         # The American point was rounded 
computerpica            12 computerpoint  # to an even 1|72 inch by computer
postscriptpoint         computerpoint     # people at some point. 
pspoint                 postscriptpoint
Q                       1|4 mm            # Used in Japanese phototypesetting
                                          # Q is for quarter
frenchprinterspoint     olddidotpoint     
didotpoint              germandidotpoint  # This seems to be the dominant value
europeanpoint           didotpoint        # for the point used in Europe
cicero                  12 didotpoint

stick                   2 inches

# Type sizes

excelsior               3 point
brilliant               3.5 point
diamondtype             4 point
pearl                   5 point
agate                   5.5 point  # Originally agate type was 14 lines per 
                                   #   inch, giving a value of 1|14 in.
ruby                    agate      # British
nonpareil               6 point
mignonette              6.5 point
emerald                 mignonette # British
minion                  7 point
brevier                 8 point
bourgeois               9 point
longprimer              10 point
smallpica               11 point
pica                    12 point
english                 14 point
columbian               16 point
greatprimer             18 point
paragon                 20 point
meridian                44 point
canon                   48 point

# German type sizes

nonplusultra            2 didotpoint
brillant                3 didotpoint
diamant                 4 didotpoint
perl                    5 didotpoint
nonpareille             6 didotpoint
kolonel                 7 didotpoint
petit                   8 didotpoint
borgis                  9 didotpoint
korpus                  10 didotpoint
corpus                  korpus
garamond                korpus
mittel                  14 didotpoint
tertia                  16 didotpoint
text                    18 didotpoint
kleine_kanon            32 didotpoint
kanon                   36 didotpoint
grobe_kanon             42 didotpoint
missal                  48 didotpoint
kleine_sabon            72 didotpoint
grobe_sabon             84 didotpoint

#
# Information theory units
#

nat                     ln(2) bits           # Entropy measured base e
hartley                 log2(10) bits        # Entropy of a uniformly
                                             #   distributed random variable
                                             #   over 10 symbols.
#
# Computer
#

bps                     bit/sec              # Sometimes the term "baud" is
                                             #   incorrectly used to refer to
                                             #   bits per second.  Baud refers
                                             #   to symbols per second.  Modern
                                             #   modems transmit several bits
                                             #   per symbol.
byte                    8 bit                # Not all machines had 8 bit
B                       byte                 #   bytes, but these days most of
                                             #   them do.  But beware: for
                                             #   transmission over modems, a
                                             #   few extra bits are used so
                                             #   there are actually 10 bits per
                                             #   byte.
nybble                  4 bits               # Half of a byte. Sometimes 
                                             #   equal to different lengths
                                             #   such as 3 bits.  
nibble                  nybble               
meg                     megabyte             # Sometimse 2^20 bytes
gig                     gigabyte             # Sometimes 2^30 bytes
                                             # See the prefix section above
                                             # for binary prefixes analagous to
                                             # the metric ones.  
jiffy                   0.01 sec     # This is defined in the Jargon File
jiffies                 jiffy        # (http://www.jargon.org) as being the
                                     # duration of a clock tick for measuring
                                     # wall-clock time.  Supposedly the value
                                     # used to be 1|60 sec or 1|50 sec
                                     # depending on the frequency of AC power,
                                     # but then 1|100 sec became more common.
                                     # On linux systems, this term is used and
                                     # for the Intel based chips, it does have
                                     # the value of .01 sec.  The Jargon File
                                     # also lists two other definitions:
                                     # millisecond, and the time taken for
                                     # light to travel one foot.
#
# Musical measures.  Musical intervals expressed as ratios.  Multiply 
# two intervals together to get the sum of the interval.  The function
# musicalcent can be used to convert ratios to cents.  
#

# Perfect intervals

octave                  2
majorsecond             musicalfifth^2 / octave
majorthird              5|4
minorthird              6|5  
musicalfourth           4|3
musicalfifth            3|2
majorsixth              musicalfourth majorthird
minorsixth              musicalfourth minorthird
majorseventh            musicalfifth majorthird
minorseventh            musicalfifth minorthird

pythagoreanthird        majorsecond musicalfifth^2 / octave
syntoniccomma           pythagoreanthird / majorthird 
pythagoreancomma        musicalfifth^12 / octave^7

# Equal tempered definitions

semitone                octave^(1|12)
musicalcent(x) [1;1]    semitone^(x/100) ; 100 log(musicalcent)/log(semitone)

#
# yarn and cloth measures
#

# yarn linear density

woolyarnrun             1600 yard/pound # 1600 yds of "number 1 yarn" weighs
                                        # a pound.  
yarncut                 300 yard/pound  # Less common system used in
                                        # Pennsylvania for wool yarn
cottonyarncount         840 yard/pound
linenyarncount          300 yard/pound  # Also used for hemp and ramie
worstedyarncount        1680 ft/pound
metricyarncount         meter/gram
denier                  1|9 tex            # used for silk and rayon
manchesteryarnnumber    drams/1000 yards   # old system used for silk
pli                     lb/in
typp                    1000 yd/lb
asbestoscut             100 yd/lb    # used for glass and asbestos yarn

tex                     gram / km    # rational metric yarn measure, meant
drex                    0.1 tex      # to be used for any kind of yarn


# yarn and cloth length

skeincotton             80*54 inch   # 80 turns of thread on a reel with a
                                     #  54 in circumference (varies for other
                                     #  kinds of thread)
cottonbolt              120 ft       # cloth measurement
woolbolt                210 ft
bolt                    cottonbolt
heer                    600 yards
cut                     300 yards    # used for wet-spun linen yarn
lea                     300 yards

#
# drug dosage
#

mcg                     microgram        # Frequently used for vitamins
iudiptheria             62.8 microgram   # IU is for international unit
iupenicillin            0.6 microgram
iuinsulin               41.67 microgram
drop                    1|20 ml          # The drop was an old "unit" that was
                                         # replaced by the minim.  But I was
                                         # told by a pharmacist that in his
                                         # profession, the conversion of 20
                                         # drops per ml is actually used. 
bloodunit               450 ml           # For whole blood.  For blood
                                         # components, a blood unit is the
                                         # quanity of the component found in a
                                         # blood unit of whole blood.  The
                                         # human body contains about 12 blood
                                         # units of whole blood.  
#
# fixup units for times when prefix handling doesn't do the job
#

hectare                 hectoare
megohm                  megaohm
kilohm                  kiloohm
microhm                 microohm
megalerg                megaerg    # 'L' added to make it pronounceable [18].

#
# Exchange rates from the New York Times, 27 July 1999
# 
# Some European currencies have permanent fixed exchange rates with
# the Euro.  These rates were taken from the EC's web site:
# http://europa.eu.int/eurobirth/rates.html
#

cent                    $ .01
argentinapeso           $ 1.0010   # Financial rate
australiadollar         0.6483 $
austriaschilling        1|13.7603 euro
belgiumfranc            1|40.3399 euro
brazilreal              0.5488 $
britainpound            1.5906 $
canadadollar            0.6625 $
chilepeso               0.001932 $  # Official rate
chinayuan               0.1208 $
colombiapeso            0.000545 $
czechkoruna             0.0287 $
denmarkkrone            0.1439 $
euro                    1.061 $    # 27 July 1999 rate from Yahoo
ecuadorsucre            0.000086 $
egyptpound              0.2930 $
finlandmarkka           1|5.94573 euro
francefranc             1|6.55957 euro
germanymark             1|1.95583 euro
greatbritainpound       britainpound
greecedrachma           0.003282 $
hongkongdollar          0.1288  $
hungaryforint           0.0042 $
indiarupee              0.0231 $    # official rate
indonesiarupiah         0.000143 $
irelandpunt             1|0.787564 euro
israelshekel            0.2439 $
italylira               1|1936.27 euro
japanyen                0.008576 $
jordandinar             1.4104 $
lebanonpound            0.000663 $
malaysiaringgit         0.2632 $
mexicopeso              0.106373 $
netherlandsguilder      1|2.20371 euro
newzealanddollar        0.5275 $
norwaykrone             0.1283 $
pakistanrupee           0.0195 $
perunewsol              0.3008 $
philippinespeso         0.0261 $
polandzloty             0.2604 $
portugalescudo          1|200.482 euro
russiaruble             0.0413 $  # Moscow Interbank Currency Exchange
saudiarabiariyal        0.2666 $
singaporedollar         0.5936 $
slovakiakoruna          0.0235 $
southafricarand         0.1630 $
southkoreawon           0.000828 $
spainpeseta             1|166.386 euro
swedenkrona             0.1210 $
switzerlandfranc        0.6644 $
taiwandollar            0.0310 $
thailandbaht            0.02675 $
turkeylira              0.000002 $
unitedarabdirham        0.2723 $
unitedkingdompound      britainpound
unitedstatesdollar      $
uruguaynewpeso          0.0870 $
venezuelabolivar        0.0016 $

mark                    germanymark
bolivar                 venezuelabolivar
peseta                  spainpeseta
rand                    southafricarand
escudo                  portugalescudo
sol                     perunewsol
guilder                 netherlandsguilder
hollandguilder          netherlandsguilder
peso                    mexicopeso
yen                     japanyen
lira                    italylira
rupee                   indiarupee
drachma                 greecedrachma
franc                   francefranc
markka                  finlandmarkka
sucre                   ecuadorsucre
poundsterling           britainpound

# ISO currency codes

AED                     unitedarabdirham
ATS                     austriaschilling
AUD                     australiadollar
BEF                     belgiumfranc
BRR                     brazilreal
CAD                     canadadollar
CHF                     switzerlandfranc
CLP                     chilepeso
COP                     colombiapeso
CZK                     czechkoruna
DEM                     germanymark
DKK                     denmarkkrone
ECS                     ecuadorsucre
EGP                     egyptpound
ESP                     spainpeseta
EUR                     euro
FIM                     finlandmarkka
FRF                     francefranc
GBP                     britainpound
GRD                     greecedrachma
HKD                     hongkongdollar
HUF                     hungaryforint
IDR                     indonesiarupiah
IEP                     irelandpunt
ILS                     israelshekel
IND                     indiarupee
ITL                     italylira
JOD                     jordandinar
JPY                     japanyen
KRW                     southkoreawon
LBP                     lebanonpound
MYR                     malaysiaringgit
MXP                     mexicopeso
NLG                     netherlandsguilder
NOK                     norwaykrone
NZD                     newzealanddollar
PEN                     perunewsol
PHP                     philippinespeso
PLZ                     polandzloty
PTE                     portugalescudo
RUR                     russiaruble
SAR                     saudiarabiariyal
SEK                     swedenkrona
SGD                     singaporedollar
SKK                     slovakiakoruna
THB                     thailandbaht
TRL                     turkeylira
TWD                     taiwandollar
USD                     $
VEB                     venezuelabolivar
XEU                     euro
ZAR                     southafricarand

UKP                     GBP        # Not an ISO code, but looks like one, and
                                   # sometimes used on usenet.

# Precious metals (27 Nov 1996 NY Times)

goldprice               $ 379 / troyounce
silverprice             $ 4.70 / troyounce

# Money on the gold standard, used in the late 19th century and early
# 20th century.

olddollargold           23.22 grains goldprice  # Used until 1934
newdollargold           96|7 grains goldprice   # After Jan 31, 1934
dollargold              newdollargold
poundgold               113 grains goldprice

# British currency

shilling                1|20 britainpound   # Before decimalisation, there
oldpence                1|12 shilling       # were 20 shillings to a pound,
                                            # each of twelve old pence
quid                    britainpound        # Slang names
fiver                   5 quid
tenner                  10 quid

#
# Units used for measuring volume of wood
#

cord                    4*4*8 ft^3   # 4 ft by 4 ft by 8 ft bundle of wood
facecord                1|2 cord
cordfoot                1|8 cord     # One foot long section of a cord
cordfeet                cordfoot
housecord               1|3 cord     # Used to sell firewood for residences, 
                                     #   often confusingly called a "cord"
boardfoot               ft^2 inch    # Usually 1 inch thick wood
boardfeet               boardfoot
fbm                     boardfoot    # feet board measure
stack                   4 yard^3     # British, used for firewood and coal [18]
rick                    4 ft 8 ft 16 inches # Stack of firewood, supposedly
                                     #   sometimes called a face cord, but this
                                     #   value is equal to 1|3 cord.  Name
                                     #   comes from an old Norse word for a
                                     #   stack of wood.  
stere                   m^3
timberfoot              ft^3         # Used for measuring solid blocks of wood
standard                120 12 ft 11 in 1.5 in  # This is the St Petersburg or
                                     #   Pittsburg standard.  Apparently the
                                     #   term is short for "standard hundred"
                                     #   which was meant to refer to 100 pieces
                                     #   of wood (deals).  However, this
                                     #   particular standard is equal to 120
                                     #   deals which are 12 ft by 11 in by 1.5
                                     #   inches (not the standard deal). 

# In Britain, the deal is apparently any piece of wood over 6 feet long, over
# 7 wide and 2.5 inches thick.  The OED doesn't give a standard size.  A piece
# of wood less than 7 inches wide is called a "batten".  This unit is now used
# exclusively for fir and pine.

deal              12 ft 11 in 2.5 in # The standard North American deal [OED]
wholedeal        12 ft 11 in 1.25 in # If it's half as thick as the standard
                                     #   deal it's called a "whole deal"!
splitdeal         12 ft 11 in 5|8 in # And half again as thick is a split deal.


#
# Gas and Liquid flow units
#

# Some obvious volumetric gas flow units (cu is short for cubic)

cumec                   m^3/s
cusec                   ft^3/s

# Conventional abbreviations for fluid flow units

gph                     gal/hr
gpm                     gal/min
mgd                     megagal/day
cfs                     ft^3/s
cfh                     ft^3/hour
cfm                     ft^3/min
lpm                     liter/min

# Miner's inch:  This is an old historic unit used in the Western  United
# States.  It is generally defined as the rate of flow through a one square
# inch hole at a specified depth such as 4 inches.  In the late 19th century,
# volume of water was sometimes measured in the "24 hour inch".  Values for the
# miner's inch were fixed by state statues.  (This information is from a web
# site operated by the Nevada Division of Water Planning:  The Water Words
# Dictionary at http://www.state.nv.us/cnr/ndwp/dict-1/waterwds.htm.)

minersinchAZ            1.5 ft^3/min
minersinchCA            1.5 ft^3/min 
minersinchMT            1.5 ft^3/min
minersinchNV            1.5 ft^3/min
minersinchOR            1.5 ft^3/min
minersinchID            1.2 ft^3/min
minersinchKS            1.2 ft^3/min
minersinchNE            1.2 ft^3/min
minersinchNM            1.2 ft^3/min
minersinchND            1.2 ft^3/min
minersinchSD            1.2 ft^3/min
minersinchUT            1.2 ft^3/min
minersinchCO            1.56 ft^3/min
minersinchBC            1.68 ft^3/min   # British Columbia

# Oceanographic flow

sverdrup                1e6 m^3 / sec   # Used to express flow of ocean
                                        # currents.  Named after Norwegian
                                        # oceanographer H. Sverdrup.  

# In vacuum science and some other applications, gas flow is measured
# as the product of volumetric flow and pressure.  This is useful
# because it makes it easy to compare with the flow at standard
# pressure (one atmosphere).  It also directly relates to the number
# of gas molecules per unit time, and hence to the mass flow if the
# molecular mass is known.

sccm                    atm cc/min     # 's' is for "standard" to indicate
sccs                    atm cc/sec     # flow at standard pressure
scfh                    atm ft^3/hour  #
scfm                    atm ft^3/min
slpm                    atm liter/min
slph                    atm liter/hour
lusec                   liter micron Hg / s  # Used in vacuum science

#
# Wire Gauge 
#
# This area is a nightmare with huge charts of wire gauge diameters
# that usually have no clear origin.  There are at least 5 competing wire gauge
# systems to add to the confusion.  The use of wire gauge is related to the
# manufacturing method: a metal rod is heated and drawn through a hole.  The
# size change can't be too big.  To get smaller wires, the process is repeated
# with a series of smaller holes.  Generally larger gauges mean smaller wires.
# The gauges often have values such as "00" and "000" which are larger sizes
# than simply "0" gauge.  In the tables that appear below, these gauges must be
# specified as negative numbers (e.g. "00" is -1, "000" is -2, etc).
# Alternatively, you can use the following units:
#

g00			 (-1)
g000			 (-2)
g0000			 (-3)
g00000			 (-4)
g000000			 (-5)
g0000000		 (-6)

# American Wire Gauge (AWG) or Brown & Sharpe Gauge appears to be the most
# important gauge. ASTM B-258 specifies that this gauge is based on geometric
# interpolation between gauge 0000, which is 0.46 inches exactly, and gauge 36
# which is 0.005 inches exactly.  Therefore, the diameter in inches of a wire
# is given by the formula 1|200 92^((36-g)/39).  Note that 92^(1/39) is close
# to 2^(1/6), so diameter is approximately halved for every 6 gauges.  For the
# repeated zero values, use negative numbers in the formula.  The same document
# also specifies rounding rules which seem to be ignored by makers of tables.
# Gauges up to 44 are to be specified with up to 4 significant figures, but no
# closer than 0.0001 inch.  Gauges from 44 to 56 are to be rounded to the
# nearest 0.00001 inch.  
#
# In addition to being used to measure wire thickness, this gauge is used to
# measure the thickness of sheets of aluminum, copper, and most metals other
# than steel, iron and zinc.

wiregauge(g) [;m] 1|200 92^((36+(-g))/39) in;36+(-39)ln(200 wiregauge/in)/ln(92)

# Next we have the SWG, the Imperial or British Standard Wire Gauge.  This one
# is piecewise linear.  It was used for aluminum sheets.

brwiregauge[in]  \
       -6 0.5    \
       -5 0.464  \
       -3 0.4    \
       -2 0.372  \
        3 0.252  \
        6 0.192  \
       10 0.128  \
       14 0.08   \
       19 0.04   \
       23 0.024  \
       26 0.018  \
       28 0.0148 \
       30 0.0124 \
       39 0.0052 \
       49 0.0012 \
       50 0.001

# The following is from the Appendix to ASTM B 258
#
#    For example, in U.S. gage, the standard for sheet metal is based on the
#    weight of the metal, not on the thickness. 16-gage is listed as
#    approximately .0625 inch thick and 40 ounces per square foot (the original
#    standard was based on wrought iron at .2778 pounds per cubic inch; steel
#    has almost entirely superseded wrought iron for sheet use, at .2833 pounds
#    per cubic inch). Smaller numbers refer to greater thickness. There is no
#    formula for converting gage to thickness or weight.
# 
# It's rather unclear from the passage above whether the plate gauge values are
# therefore wrong if steel is being used.  Reference [15] states that steel is
# in fact measured using this gauge (under the name Manufacturers' Standard
# Gauge) with a density of 501.84 lb/ft3 = 0.2904 lb/in3 used for steel.
# But this doesn't seem to be the correct density of steel (.2833 lb/in3 is
# closer).  
#
# This gauge was established in 1893 for purposes of taxation.

# Old plate gauge for iron

plategauge[(oz/ft^2)/(480*lb/ft^3)] \
      -5 300   \
       1 180   \
      14  50   \
      16  40   \
      17  36   \
      20  24   \
      26  12   \
      31   7   \
      36   4.5 \
      38   4 

# Manufacturers Standard Gage

stdgauge[(oz/ft^2)/(501.84*lb/ft^3)] \
      -5 300   \
       1 180   \
      14  50   \
      16  40   \
      17  36   \
      20  24   \
      26  12   \
      31   7   \
      36   4.5 \
      38   4 

# A special gauge is used for zinc sheet metal.  Notice that larger gauges
# indicate thicker sheets. 

zincgauge[in]    \
        1 0.002  \
       10 0.02   \
       15 0.04   \
       19 0.06   \
       23 0.1    \
       24 0.125  \
       27 0.5    \
       28 1

# USA ring sizes.  Several slightly different definitions seem to be in
# circulation.  According to [15], the interior diameter of size n ring in
# inches is 0.32 n + 0.458 for n ranging from 3 to 13.5 by steps of 0.5.  The
# size 2 ring is inconsistently 0.538in and no 2.5 size is listed.  
#
# However, other sources list 0.455 + 0.0326 n and 0.4525 + 0.0324 n as the
# diameter and list no special case for size 2.  (Or alternatively they are
# 1.43 + .102 n and 1.4216+.1018 n for measuring circumference in inches.)  One
# reference claimed that the original system was that each size was 1|10 inch
# circumference, but that source doesn't have an explanation for the modern
# system which is somewhat different.
#
# This table gives circumferences as listed in [15].  

ringsize(n) [;in] (1.4216+.1018 n) in ; (ringsize/in + (-1.4216))/.1018

size2ring               0.538 in pi
size3ring               0.554 in pi
size3.5ring             0.570 in pi
size4ring               0.586 in pi
size4.5ring             0.602 in pi
size5ring               0.618 in pi
size5.5ring             0.634 in pi
size6ring               0.650 in pi
size6.5ring             0.666 in pi
size7ring               0.682 in pi
size7.5ring             0.698 in pi
size8ring               0.714 in pi
size8.5ring             0.730 in pi
size9ring               0.746 in pi
size9.5ring             0.762 in pi
size10ring              0.778 in pi
size10.5ring            0.794 in pi
size11ring              0.810 in pi
size11.5ring            0.826 in pi
size12ring              0.842 in pi
size12.5ring            0.858 in pi
size13ring              0.874 in pi
size13.5ring            0.890 in pi

# Old practice in the UK measured rings using the "Wheatsheaf gauge" with sizes
# specified alphabetically and based on the ring inside diameter in steps of
# 1|64 inch.  This system was replaced in 1987 by British Standard 6820 which
# specifies sizes based on circumference.  Each size is 1.25 mm different from
# the preceding size.  The baseline is size C which is 40 mm circumference.
# The new sizes are close to the old ones.  Sometimes it's necessary to go
# beyond size Z to Z+1, Z+2, etc.  

sizeAring               37.50 mm
sizeBring               38.75 mm
sizeCring               40.00 mm
sizeDring               41.25 mm
sizeEring               42.50 mm
sizeFring               43.75 mm
sizeGring               45.00 mm
sizeHring               46.25 mm
sizeIring               47.50 mm
sizeJring               48.75 mm
sizeKring               50.00 mm
sizeLring               51.25 mm
sizeMring               52.50 mm
sizeNring               53.75 mm
sizeOring               55.00 mm
sizePring               56.25 mm
sizeQring               57.50 mm
sizeRring               58.75 mm
sizeSring               60.00 mm
sizeTring               61.25 mm
sizeUring               62.50 mm
sizeVring               63.75 mm
sizeWring               65.00 mm
sizeXring               66.25 mm
sizeYring               67.50 mm
sizeZring               68.75 mm

# Japanese sizes start with size 1 at a 13mm inside diameter and each size is
# 1|3 mm larger in diameter than the previous one.  They are multiplied by pi
# to give circumference. 

jpringsize(n)     [;mm] (38|3 + n/3) pi mm ; 3 jpringsize/ pi mm + (-38)

# The European ring sizes are the length of the circumference in mm minus 40.

euringsize(n)     [;mm] (n+40) mm ; euringsize/mm + (-40)

#
# Abbreviations
#

mph                     mile/hr
mpg                     mile/gal
kph                     km/hr
fL                      footlambert
fpm                     ft/min
fps                     ft/s
rpm                     rev/min
rps                     rev/sec
mi                      mile
mbh                     1e3 btu/hour
mcm                     1e3 circularmil
ipy                     inch/year    # used for corrosion rates
ccf                     100 ft^3     # used for selling water [18]
Mcf                     1000 ft^3    # not million cubic feet [18]

#
# Compatibility units with unix version
#

pa                      Pa
ev                      eV
hg                      Hg
oe                      Oe
mh                      mH
us                      microsec
rd                      rod
pf                      pF
gr                      grain
nt                      N
hz                      Hz
hd                      hogshead
dry                     drygallon/gallon
imperial                brgallon/gallon   # This is a dubious definition
                                          # since it fails for fluid ounces
                                          # and all units derived from fluid
                                          # ounces.  
nmile                   nauticalmile
beV                     GeV
bev                     beV
coul                    C

#
# Radioactivity units
#

becquerel               /s           # Activity of radioactive source
Bq                      becquerel    #
curie                   3.7e10 Bq    # Defined in 1910 as the radioactivity
Ci                      curie        # emitted by the amount of radon that is
                                     # in equilibrium with 1 gram of radium.
rutherford              1e6 Bq       #

gray                    J/kg         # Absorbed dose of radiation
Gy                      gray         #
rad                     1e-2 Gy      # From Radiation Absorbed Dose
rep                     8.38 mGy     # Roentgen Equivalent Physical, the amount
                                     #   of radiation which , absorbed in the
                                     #   body, would liberate the same amount
                                     #   of energy as 1 roentgen of X rays
                                     #   would, or 97 ergs.

sievert                 J/kg         # Dose equivalent:  dosage that has the
Sv                      sievert      #   same effect on human tissues as 200
rem                     1e-2 Sv      #   keV X-rays.  Different types of
                                     #   radiation are weighted by the
                                     #   Relative Biological Effectiveness
                                     #   (RBE).
                                     #
                                     #      Radiation type       RBE
                                     #       X-ray, gamma ray     1
                                     #       beta rays, > 1 MeV   1
                                     #       beta rays, < 1 MeV  1.08
                                     #       neutrons, < 1 MeV   4-5
                                     #       neutrons, 1-10 MeV   10
                                     #       protons, 1 MeV      8.5
                                     #       protons, .1 MeV      10
                                     #       alpha, 5 MeV         15
                                     #       alpha, 1 MeV         20
                                     #
                                     #   The energies are the kinetic energy
                                     #   of the particles.  Slower particles
                                     #   interact more, so they are more
                                     #   effective ionizers, and hence have
                                     #   higher RBE values.
                                     #
                                     # rem stands for Roentgen Equivalent
                                     # Mammal

roentgen              2.58e-4 C / kg # Ionizing radiation that produces
                                     #   1 statcoulomb of charge in 1 cc of
                                     #   dry air at stp.
rontgen                 roentgen     # Sometimes it appears spelled this way
sievertunit             8.38 rontgen # Unit of gamma ray dose delivered in one
                                     #   hour at a distance of 1 cm from a
                                     #   point source of 1 mg of radium
                                     #   enclosed in platinum .5 mm thick.

eman                    1e-7 Ci/m^3  # radioactive concentration
mache                   3.7e-7 Ci/m^3

#
# Atomic weights.  The atomic weight of an element is the ratio of the mass of
# a mole of the element to 1|12 of a mole of Carbon 12.  The Standard Atomic
# Weights apply to the elements as they occur naturally on earth.  Elements
# which do not occur naturally or which occur with wide isotopic variability do
# not have Standard Atomic Weights.  For these elements, the atomic weight is
# based on the longest lived isotope, as marked in the comments.  In some
# cases, the comment for these entries also gives a number which is an atomic
# weight for a different isotope that may be of more interest than the longest
# lived isotope.
#

actinium                227.0278
aluminum                26.981539
americium               243.0614     # Longest lived. 241.06
antimony                121.760      
argon                   39.948
arsenic                 74.92159
astatine                209.9871     # Longest lived
barium                  137.327
berkelium               247.0703     # Longest lived. 249.08
beryllium               9.012182
bismuth                 208.98037
boron                   10.811
bromine                 79.904
cadmium                 112.411
calcium                 40.078
californium             251.0796     # Longest lived.  252.08
carbon                  12.011
cerium                  140.115
cesium                  132.90543
chlorine                35.4527
chromium                51.9961
cobalt                  58.93320
copper                  63.546
curium                  247.0703
dysprosium              162.50
einsteinium             252.083      # Longest lived 
erbium                  167.26
europium                151.965
fermium                 257.0951     # Longest lived
fluorine                18.9984032
francium                223.0197     # Longest lived
gadolinium              157.25
gallium                 69.723
germanium               72.61
gold                    196.96654
hafnium                 178.49
helium                  4.002602
holmium                 164.93032
hydrogen                1.00794
indium                  114.818
iodine                  126.90447
iridium                 192.217
iron                    55.845
krypton                 83.80
lanthanum               138.9055
lawrencium              262.11       # Longest lived
lead                    207.2
lithium                 6.941
lutetium                174.967
magnesium               24.3050
manganese               54.93805
mendelevium             258.10       # Longest lived
mercury                 200.59
molybdenum              95.94
neodymium               144.24
neon                    20.1797
neptunium               237.0482
nickel                  58.6934
niobium                 92.90638
nitrogen                14.00674
nobelium                259.1009     # Longest lived
osmium                  190.23
oxygen                  15.9994
palladium               106.42
phosphorus              30.973762
platinum                195.08
plutonium               244.0642     # Longest lived.  239.05
polonium                208.9824     # Longest lived.  209.98
potassium               39.0983
praseodymium            140.90765
promethium              144.9127     # Longest lived.  146.92
protactinium            231.03588
radium                  226.0254
radon                   222.0176     # Longest lived
rhenium                 186.207
rhodium                 102.90550
rubidium                85.4678
ruthenium               101.07
samarium                150.36
scandium                44.955910
selenium                78.96
silicon                 28.0855
silver                  107.8682
sodium                  22.989768
strontium               87.62
sulfur                  32.066
tantalum                180.9479
technetium              97.9072      # Longest lived.  98.906
tellurium               127.60
terbium                 158.92534
thallium                204.3833
thorium                 232.0381
thullium                168.93421
tin                     118.710
titanium                47.867
tungsten                183.84
uranium                 238.0289
vanadium                50.9415
xenon                   131.29
ytterbium               173.04
yttrium                 88.90585
zinc                    65.39
zirconium               91.224

#
# A few German units as currently in use.
#

zentner                 50 kg
doppelzentner           2 zentner
pfund                   500 g

#
# Old French distance measures, from French Weights and Measures
# Before the Revolution by Zupko
#

frenchfoot              4500|13853 m      # pied de roi, the standard of Paris.
pied                    frenchfoot        #   Half of the hashimicubit,
frenchfeet              frenchfoot        #   instituted by Charlemagne.
frenchinch              1|12 frenchfoot   #   This exact definition comes from
frenchthumb             frenchinch        #   a law passed on 10 Dec 1799 which
pouce                   frenchthumb       #   fixed the meter at 
                                          #   3 frenchfeet + 11.296 lignes.
frenchline              1|12 frenchinch   # This is supposed to be the size
ligne                   frenchline        #   of the average barleycorn
frenchpoint             1|12 frenchline
toise                   6 frenchfeet
arpent                  180^2 pied^2      # The arpent is 100 square perches,
                                          # but the perche seems to vary a lot
                                          # and can be 18 feet, 20 feet, or 22
                                          # feet.  This measure was described
                                          # as being in common use in Canada in
                                          # 1934 (Websters 2nd).  The value
                                          # given here is the Paris standard
                                          # arpent.
#
# Before the Imperial Weights and Measures Act of 1824, various different
# weights and measures were in use in different places.
#

# Scots linear measure

scotsinch        1.00540054 UKinch
scotslink        1|100 scotschain
scotsfoot        12 scotsinch
scotsfeet        scotsfoot
scotsell         37 scotsinch
scotsfall        6 scotsell
scotschain       4 scotsfall
scotsfurlong     10 scotschain
scotsmile        8 scotsfurlong

# Scots area measure

scotsrood        40 scotsfall^2
scotsacre        4 scotsrood
nook             20 acres     # Given in [18] with English acres; apparently
                              # developed after the switch to Imperial units.
# Irish linear measure

irishinch       UKinch
irishpalm       3 irishinch
irishspan       3 irishpalm
irishfoot       12 irishinch
irishfeet       irishfoot
irishcubit      18 irishinch
irishyard       3 irishfeet
irishpace       5 irishfeet
irishfathom     6 irishfeet
irishpole       7 irishyard      # Only these values
irishperch      irishpole        # are different from
irishchain      4 irishperch     # the British Imperial
irishlink       1|100 irishchain # or English values for
irishfurlong    10 irishchain    # these lengths.
irishmile       8 irishfurlong   #

#  Irish area measure

irishrood       40 irishpole^2
irishacre       4 irishrood

# English wine capacity measures (Winchester measures)

winepint       1|2 winequart
winequart      1|4 winegallon
winegallon     231 UKinch^3   # Sometimes called the Winchester Wine Gallon,
                              # it was legalized in 1707 by Queen Anne, and
                              # given the definition of 231 cubic inches.  It
                              # had been in use for a while as 8 pounds of wine
                              # using a merchant's pound of 7200 grains or
                              # 15 troy ounces.  (The old mercantile pound had
                              # been 15 tower ounces.)
winerundlet    18 winegallon
winebarrel     31.5 winegallon
winetierce     42 winegallon
winehogshead   2 winebarrel
winepuncheon   2 winetierce
winebutt       2 winehogshead
winepipe       winebutt
winetun        2 winebutt

# English beer and ale measures used 1803-1824 and used for beer before 1688

beerpint       1|2 beerquart
beerquart      1|4 beergallon
beergallon     282 UKinch^3
beerbarrel     36 beergallon
beerhogshead   1.5 beerbarrel

# English ale measures used from 1688-1803 for both ale and beer

alepint        1|2 alequart
alequart       1|4 alegallon
alegallon      beergallon
alebarrel      34 alegallon
alehogshead    1.5 alebarrel

# Scots capacity measure

scotsgill      1|4 mutchkin
mutchkin       1|2 choppin
choppin        1|2 scotspint
scotspint      1|2 scotsquart
scotsquart     1|4 scotsgallon
scotsgallon    827.232 UKinch^3
scotsbarrel    8 scotsgallon
jug            scotspint

# Scots dry capacity measure

scotswheatlippy   137.333 UKinch^3    # Also used for peas, beans, rye, salt
scotswheatlippies scotswheatlippy
scotswheatpeck    4 scotswheatlippy
scotswheatfirlot  4 scotswheatpeck
scotswheatboll    4 scotswheatfirlot
scotswheatchalder 16 scotswheatboll

scotsoatlippy     200.345 UKinch^3    # Also used for barley and malt
scotsoatlippies   scotsoatlippy
scotsoatpeck      4 scotsoatlippy
scotsoatfirlot    4 scotsoatpeck
scotsoatboll      4 scotsoatfirlot
scotsoatchalder   16 scotsoatboll

# Scots Tron weight

trondrop       1|16 tronounce
tronounce      1|20 tronpound
tronpound      9520 grain
tronstone      16 tronpound

# Irish liquid capacity measure

irishnoggin    1|4 irishpint
irishpint      1|2 irishquart
irishquart     1|2 irishpottle
irishpottle    1|2 irishgallon
irishgallon    217.6 UKinch^3
irishrundlet   18 irishgallon
irishbarrel    31.5 irishgallon
irishtierce    42 irishgallon
irishhogshead  2 irishbarrel
irishpuncheon  2 irishtierce
irishpipe      2 irishhogshead
irishtun       2 irishpipe

# Irish dry capacity measure

irishpeck      2 irishgallon
irishbushel    4 irishpeck
irishstrike    2 irishbushel
irishdrybarrel 2 irishstrike
irishquarter   2 irishbarrel

# English Tower weights, abolished in 1528

towerpound       5400 grain
towerounce       1|12 towerpound
towerpennyweight 1|20 towerounce

# English Mercantile weights, used since the late 12th century

mercpound      6750 grain
mercounce      1|15 mercpound
mercpennyweight 1|20 mercounce

# English weights for lead

leadstone     12.5 lb
fotmal        70 lb
leadwey       14 leadstone
fothers       12 leadwey

# English Hay measure

newhaytruss 60 lb             # New and old here seem to refer to "new"
newhayload  36 newhaytruss    # hay and "old" hay rather than a new unit
oldhaytruss 56 lb             # and an old unit.
oldhayload  36 oldhaytruss

# English wool measure

woolclove   7 lb
woolstone   2 woolclove
wooltod     2 woolstone
woolwey     13 woolstone
woolsack    2 woolwey
woolsarpler 2 woolsack
woollast    6 woolsarpler

#
# Ancient history units:  There tends to be uncertainty in the definitions
#                         of the units in this section
# These units are from [11]

# Roman measure.  The Romans had a well defined distance measure, but their
# measures of weight were poor.  They adopted local weights in different
# regions without distinguishing among them so that there are half a dozen
# different Roman "standard" weight systems.  

romanfoot    296 mm          # There is some uncertainty in this definition
romanfeet    romanfoot       # from which all the other units are derived.
pes          romanfoot       # This value appears in numerous sources. In "The
pedes        romanfoot       # Roman Land Surveyors", Dilke gives 295.7 mm.
romaninch    1|12 romanfoot  # The subdivisions of the Roman foot have the
romandigit   1|16 romanfoot  #   same names as the subdivisions of the pound,
romanpalm    1|4 romanfoot   #   but we can't have the names for different
romancubit   18 romaninch    #   units.
romanpace    5 romanfeet     # Roman double pace (basic military unit)
passus       romanpace
romanperch   10 romanfeet
stade        125 romanpaces
stadia       stade
stadium      stade
romanmile    8 stadia        # 1000 paces
romanleague  1.5 romanmile
schoenus     4 romanmile

# Other values for the Roman foot (from Dilke)

earlyromanfoot    29.73 cm
pesdrusianus      33.3 cm    # or 33.35 cm, used in Gaul & Germany in 1st c BC
lateromanfoot     29.42 cm

# Roman areas

actuslength  120 romanfeet     # length of a Roman furrow
actus        120*4 romanfeet^2 # area of the furrow
squareactus  120^2 romanfeet^2 # actus quadratus
acnua        squareactus
iugerum      2 squareactus
iugera       iugerum
jugerum      iugerum
jugera       iugerum
heredium     2 iugera          # heritable plot
heredia      heredium
centuria     100 heredia
centurium    centuria

# Roman volumes

sextarius       35.4 in^3      # Basic unit of Roman volume.  As always,
sextarii        sextarius      # there is uncertainty.  Six large Roman
                               # measures survive with volumes ranging from
                               # 34.4 in^3 to 39.55 in^3.  Three of them
                               # cluster around the size given here.
                               #
                               # But the values for this unit vary wildly
                               # in other sources.  One reference  gives 0.547
                               # liters, but then says the amphora is a 
                               # cubic Roman foot.  This gives a value for the
                               # sextarius of 0.540 liters.  And the
                               # encyclopedia Brittanica lists 0.53 liters for
                               # this unit.  Both [7] and [11], which were
                               # written by scholars of weights and measures,
                               # give the value of 35.4 cubic inches.  
cochlearia      1|48 sextarius
cyathi          1|12 sextarius
acetabula       1|8 sextarius
quartaria       1|4 sextarius
quartarius      quartaria
heminae         1|2 sextarius
hemina          heminae
cheonix         1.5 sextarii

# Dry volume measures (usually)

semodius        8 sextarius
semodii         semodius
modius          16 sextarius
modii           modius

# Liquid volume measures (usually)

congius         12 heminae
congii          congius
amphora         8 congii
amphorae        amphora      # Also a dry volume measure
culleus         20 amphorae
quadrantal      amphora

# Roman weights

libra           5052 grain   # The Roman pound varied significantly
librae          libra        # from 4210 grains to 5232 grains.  Most of
romanpound      libra        # the standards were obtained from the weight
uncia           1|12 libra   # of particular coins.  The one given here is
unciae          uncia        # based on the Gold Aureus of Augustus which
romanounce      uncia        # was in use from BC 27 to AD 296.  
deunx           11 uncia
dextans         10 uncia
dodrans         9 uncia
bes             8 uncia
seprunx         7 uncia
semis           6 uncia
quincunx        5 uncia
triens          4 uncia
quadrans        3 uncia
sextans         2 uncia
sescuncia       1.5 uncia
semuncia        1|2 uncia
siscilius       1|4 uncia
sextula         1|6 uncia
semisextula     1|12 uncia
scriptulum      1|24 uncia
scrupula        scriptulum
romanobol       1|2 scrupula

romanaspound    4210 grain    # Old pound based on bronze coinage, the  
                              # earliest money of Rome BC 338 to BC 268. 

# Egyptian length measure

egyptianroyalcubit      20.63 in    # plus or minus .2 in
egyptianpalm            1|7 egyptianroyalcubit
egyptiandigit           1|4 egyptianpalm
egyptianshortcubit      6 egyptianpalm

doubleremen             29.16 in  # Length of the diagonal of a square with
remendigit       1|40 doubleremen # side length of 1 royal egyptian cubit.
                                  # This is divided into 40 digits which are
                                  # not the same size as the digits based on
                                  # the royal cubit.

# Greek length measures

greekfoot               12.45 in      # Listed as being derived from the 
greekfeet               greekfoot     # Egyptian Royal cubit in [11].  It is
greekcubit              1.5 greekfoot # said to be 3|5 of a 20.75 in cubit.
pous                    greekfoot
podes                   greekfoot
orguia                  6 greekfoot
greekfathom             orguia
stadion                 100 orguia
akaina                  10 greekfeet
plethron                10 akaina
greekfinger             1|16 greekfoot
homericcubit            20 greekfingers  # Elbow to end of knuckles.
shortgreekcubit         18 greekfingers  # Elbow to start of fingers.

ionicfoot               296 mm    
doricfoot               326 mm

olympiccubit            25 remendigit    # These olympic measures were not as
olympicfoot             2|3 olympiccubit # common as the other greek measures.
olympicfinger           1|16 olympicfoot # They were used in agriculture.
olympicfeet             olympicfoot
olympicdakylos          olympicfinger
olympicpalm             1|4 olympicfoot
olympicpalestra         olympicpalm
olympicspithame         3|4 foot
olympicspan             olympicspithame
olympicbema             2.5 olympicfeet
olympicpace             olympicbema
olympicorguia           6 olympicfeet
olympicfathom           olympicorguia
olympiccord             60 olympicfeet
olympicamma             olympiccord
olympicplethron         100 olympicfeet
olympicstadion          600 olympicfeet

# Greek capacity measure

greekkotyle             270 ml           # This approximate value is obtained
xestes                  2 greekkotyle    # from two earthenware vessels that
khous                   12 greekkotyle   # were reconstructed from fragments.
metretes                12 khous         # The kotyle is a day's corn ration
choinix                 4 greekkotyle    # for one man. 
hekteos                 8 choinix
medimnos                6 hekteos

# Greek weight.  Two weight standards were used, an Aegina standard based
# on the Beqa shekel and an Athens (attic) standard.

aeginastater            192 grain        # Varies up to 199 grain
aeginadrachmae          1|2 aeginastater
aeginaobol              1|6 aeginadrachmae
aeginamina              50 aeginastaters
aeginatalent            60 aeginamina

atticstater             135 grain        # Varies 134-138 grain
atticdrachmae           1|2 atticstater
atticobol               1|6 atticdrachmae
atticmina               50 atticstaters
attictalent             60 atticmina

# "Northern" cubit and foot.  This was used by the pre-Aryan civilization in
# the Indus valley.  It was used in Mesopotamia, Egypt, North Africa, China,
# central and Western Europe until modern times when it was displaced by
# the metric system.

northerncubit           26.6 in           # plus/minus .2 in
northernfoot            1|2 northerncubit

sumeriancubit           495 mm
kus                     sumeriancubit
sumerianfoot            2|3 sumeriancubit

assyriancubit           21.6 in
assyrianfoot            1|2 assyriancubit
assyrianpalm            1|3 assyrianfoot
assyriansusi            1|20 assyrianpalm
susi                    assyriansusi
persianroyalcubit       7 assyrianpalm


# Arabic measures.  The arabic standards were meticulously kept.  Glass weights
# accurate to .2 grains were made during AD 714-900.

hashimicubit            25.56 in          # Standard of linear measure used
                                          # in Persian dominions of the Arabic
                                          # empire 7-8th cent.  Is equal to two
                                          # French feet.

blackcubit              21.28 in
arabicfeet              1|2 blackcubit
arabicfoot              arabicfeet
arabicinch              1|12 arabicfoot
arabicmile              4000 blackcubit

silverdirhem            45 grain  # The weights were derived from these two
tradedirhem             48 grain  # units with two identically named systems
                                  # used for silver and used for trade purposes

silverkirat             1|16 silverdirhem
silverwukiyeh           10 silverdirhem
silverrotl              12 silverwukiyeh
arabicsilverpound       silverrotl

tradekirat              1|16 tradedirhem
tradewukiyeh            10 tradedirhem
traderotl               12 tradewukiyeh
barabictradepound        traderotl

# Miscellaneous ancient units

parasang                3.5 mile # Persian unit of length usually thought
                                 # to be between 3 and 3.5 miles
biblicalcubit           21.8 in
hebrewcubit             17.58 in
li                      10|27.8 mile  # Chinese unit of length
                                      #   100 li is considered a day's march
liang                   11|3 oz       # Chinese weight unit


# Medieval time units.  According to the OED, these appear in Du Cange
# by Papias.

timepoint               1|5 hour  # also given as 1|4
timeminute              1|10 hour
timeostent              1|60 hour
timeounce               1|8 timeostent
timeatom                1|47 timeounce

# Given in [15], these subdivisions of the grain were supposedly used
# by jewelers.  The mite may have been used but the blanc could not
# have been accurately measured.

mite                    1|20 grain     
droit                   1|24 mite
periot                  1|20 droit
blanc                   1|24 periot    

#
# Some definitions using ISO 8859-1 characters
#

¼-                      1|4
½-                      1|2
¾-                      3|4
µ-                      micro
¢                       cent
£                       britainpound
¥                       japanyen
ångström                angstrom
Å                       angstrom
röntgen                 roentgen
°C                      degC
°F                      degF
°K                      K             # °K is incorrect notation
°R                      degR
°                       degree


############################################################################
#
# The following units were in the unix units database but do not appear in
# this file:
#
#      wey        used for cheese, salt and other goods.  Measured mass or
#      waymass    volume depending on what was measured and where the measuring
#                 took place.  A wey of cheese ranged from 200 to 324 pounds.
#
#      sack       No precise definition
#
#      spindle    The length depends on the type of yarn
#
#      block      Defined variously on different computer systems
#
#      erlang     A unit of telephone traffic defined variously.  
#                 Omitted because there are no other units for this
#                 dimension.  Is this true?  What about CCS = 1/36 erlang?
#                 Erlang is supposed to be dimensionless.  One erlang means
#                 a single channel occupied for one hour.
#
############################################################################