# -: G :-

Glossary: Home Tables A B C D E F G H I J K L M N O P Q R S T Th U V W X Y Z

gallon *
A base unit of capacity in the imperial system.
There are values usually quoted for the imperial gallon, depending on the 1820 and 1898 calibrations of the measures.
code G0 - 1818 GM - cu in gr / cu in explanation 276.48 253.1828 The intent here was 1000 oz per cubic foot [never legal] 276.8 252.891 The conversion by 10 lb metric water 277.200 252.525 UK gallon = 1.2 US gallon exactly = 231*6/5. 277.274 252.4578 The gallon as implemented on 1824 measures 277.420 252.325 The gallon as implemented by Beniot's measure
See also gallon, gallons in cubic inches.
gaussian scales *
One can add to the density-velocity-time, the derived gaussian units, which require that density has a square-root. By setting Density as 200, one can achieve units for these, as follows.
Indirect units refer to quantities that are measured in the opposing scale, eg magnetic charge in ESU or electric current in EMU.
Direct CGS EM quantity ES quantity Rule N - m permeability e permittivity -10 mjar C magn. cap C capacitance 1 mmic L inductance - 1 Gs B flux density D flux density 110 H magn. field E ele. field 120 Gb U magn. potential V elect potential 131 Bi Y ampere current - 131 Mx FI magnetic flux PSI elect flux 132 Fr P magnetic charge Q electric charge 132
Under UES rule N, one sets for vacuum permitivity and permeability to both be 1/c. This allows electric constant ec = [epsilon]c, and mc = [mu]c to be dimensionless. The effect of this is to merge the EM and ES units, into a single practical size (see fpsc for examples.
To make rule N work, one has to adjust the mechanical quantities (ie the ones starting 200) by 10, eg Mass (200) -> 210.
See also DC-triangle, for the effect of adding a fourth dimension.
Gee-pound *
An alternate name for the slug. The prefix gee- can be taken to be either a numeric or system prefix.
One might also derive a name for pound as force, as gee-poundal.
Geodecimal System *
A system that 'corrects' the metric system, by using a decimal division of the circle direct. It is normally used with hundred-numbers, rather than thousand-number.
Day \ 10 hours \ 100 minutes \ 100 seconds
Circle \ 100 degrees \ 100 minutes \ 100 seconds
earth minute = mile (4 km) \ 100 \ 100 rod \ 100 \ 100
cu rood = 64 kg \ 100 pound \ 100 drams \ 100 grains
The values of the constants (like the size of the earth), is taken to be identical to the metric system.
Geodetic System *
A large-scale triangulation of the Earth for survey purposes. The process fixes the main triangulation points for lesser surveys.
In the former British Empire, the main geodetic scalings were done by Captian Clarke in the 1860's. This is now largely being displaced by the more recent satellite surveys.
Scale metre in inch Conversion Comment
Airy 1830 39.369 981 983 435 log10(foot/cm) = 1.48401603 Foot of 1796
Beniot A 1895 39.370 113 184 701 1 yard = 0.9143992 m UB
Beniot B 1895 39.370 113 000 000 39.370 113 in = 1 metre -
Bessel 1841 36.941 333 329 898 3272077.14 t = 6377397.155 m Ellipsoid a
Clarke 39.370 432 014 867 1 foot = 0.304797265 m see UC
Clarke 1865 39.369 971 101 347 1 yard = 0.9144025 metre -
German Legal 39.999 456 127 395 1 GLM = 1.000013597 m -
Gold Coast 39.370 116 175 156 20926201 feet = 6378300 m Gold Coast
Indian Foot 39.370 142 000 000 39.370142 inch = 1 metre Indian
International 39.370 078 740 157 1 yard = 0.9144 m UI
Sears 1922 39.370 147 000 000 39.370 147 inch = 1 metre UK
US Survey 39.370 000 000 000 39.37 inch = 1 metre US

Airy's 1830: Original definition is a=20923713 and b=20853810 feet of 1796. For the 1936 retriangulation OSGB defines the relationship of feet of 1796 to the International metre through log(1.48401603) exactly a is given as 6377563.396 metre
Bessel 1841: Original Bessel definition is a=3272077.14 and b=3261139.33 toise. This used a weighted mean of values from several authors but did not account for differences in the length of the various toise: the Bessel toise is therefore of uncertain length. a is given as 6377397.155 metres.
The german Legal system is used in Namabia, and is based on a modified version of Bessel's values.
Geographic Pi *
The value of earth equator divided by polar axis
3.141 592 653 59 pi, geometric value. 20 / polar typical value for this value value in nature, on pi*eq / polar polar: polar radius in metres eq: equatorial radius in metres
Geographic System *
In the geographic hypothesis, the earth is a sphere with a defined diameter. Since the spheric geometry measures length in terms of angle, the units of length are made to align with angle as follows.
EC is the Earth circle, the division shows until the first named unit, the assorted angle divisions: thus, EC \ 360 \ 60 mile means that the circle divides into 360 degrees of 60 minutes, each minute a mile
Te conversion factor from geographic to regular measures is a definition of some size of the world, although the units may be defined.
Circle \ 360 degree \ 60 min \ 60 sec \ 60 thir
EC \ 360 \ 60 mile \ 1000 fathom \ 6 foot \ 12 inch \ 12 line
EC \ 360 \ 60 mile \ 60 chain \ 60 cubit \ 60 barleycorn
EC \ 360 \ 60 mile \ 1000 fathom \ 1000 line
Circle \ 400 grade \ 100 min \ 100 sec
EC \ 400 \ 100 kilometre \ 1000 metre
Circle \ 120 degree \ 120 minute \ 120 second \ 120 third
EC \ 120 \ 120 mrinal \ 120 segment \ 120 links
Circle \ 100 deg \ 100 min \ 100 sec : Geodecimal
EC \ 100 \ 100 mile \ 100 chain \ 100 rod \ 100 line
It should be noted that a cubic geographic foot of water contains very near 60 french pounds of water.
Also, it is noted that where the cubit per second is the same as a mile per hour, that a cubic cubit of water is nearly 300 avoirdepoise pounds. This makes for a good weight for a seam.
A geographic metre is 3.24 geographic feet.
A geographic rod is 1.296 geo feet or 400 geo. mm long
A geographic link is 7.5 inches long.
- G foot / UI in metre in G inch Definition
GRS (a) 12.133 230 272 38.937 771 250 169 Polar 6356752.314 m
Berriman 12.150 000 000 38.884 028 385 340 1 metre = 54 digits
Metric 12.151 258 870 38.880 000 000 000 EC = 40,000 km
International 12.152 230 971 38.876 889 848 812 Mile = 1852 metre
GRS (a+b)/2 12.153 638 911 38.872 386 150 134 -
Nines 12.156 938 257 480 38.861 836 333 765 1.03 lignt nanoseconds
tiof 12.158 406 669 38.857 142 857 142 geo ft = 12.6 tiof in
Admiralty 12.160 000 000 38.852 051 388 313 1 mile = 6080 ft
Sphere 12.160 425 048 38.850 693 375 67 Radius 6371000 km
GRS (2a+b)/3 12.160 441 079 38.850 639 887 710 mean
Neal 12.165 120 000 38.835 699 5814 833 EC = 24883.2 miles
GRS (b) 12.174 047 549 38.807 220 273 963 a = 6378137 km
The product of the two columns is 60,000/127.
The GRS(1980) model of the earth is provided to give some real references.
The sphere is a geodetic model.
Geometric Units *
The geometric units (foot, inch, line) refer to a decimal division of these units, usually preserving the duodecimal foot.
germanic system *
A fantasy system representing germanic traditions. In essence, a kind of default value for units, where a value is not clear.
Length: mile 6000, furlong 600, fathom 6, ell 2, foot 1, inch 1/12
Weight: ton 2400, cwt 120, stone 20 or 15, pound 1, ounce 1/16
Weight: pound 7680, ounce 480, ledd 240, drachm 60, pennywt 24, scruple 20, grain 1
ghurry *
An indian water-clock instrument, and hence the unit of time it measures, being a measure of day \ 60 ghurry. The word also becomes clock, bell, gong.
In British india, the gurry becomes an hour of 60 min.
cf our use of o'clock to measure the hours.
The ghurry \ 60 pala \ 60 vipala.
Gold Coast Foot *
A conversion factor setting 6378300.0 metres to 20926201.0 feet.
Used in Ghana and some adjacent parts of British west Africa prior to metrication, except for the metrication of projection defining parameters when British foot (Sears 1922) used.
Source: Ordnance Survey International
golden jump *
A alternate method for correcting easter by moving the moon into the next station when a correction is required.
The effect is to add a correction of eight over the year, so that GN 1, is followed normally by 2, but corrected to 2+8 = 10.
Because a goldern jumb is done only 19 times in a month, rather than 30, the correction is needed less often, typically every 360 years.
A golden jump corresponds to 30 australs, see also Epact Shift.
golden number *
The number the year is of the lunar cycle, used in calculating Easter. The number runs from 1 to 19, representing the remainder when the year is divided by 19. So 2000 is GN 5.
Googol Systems *
Any system that integrates dimension number and unit-exponent into the same number. Under such a system, one might have more than one base unit (eg metre = 1100, cm = 1098), where the number serves both as exponent and measure.
One might couple googol-numbers with magnetic numbers.
Gorem *
A temperature scale based on making the greater portion of the observed temperatures fall in the same hundred, and also making fixed points fall on decimal isotherms. In practice, the scale is always used as an absolute version.
970 Gorems = maximum thremm of water
560 Gorems = water boils
410 Gorems = triple point of water
0 Gorems = Absolute zero
Degrees Gorem refers to a close scale, based on ip=410, bp = 560.
A similar scale might be made by taking four-fifths of this, giving a scale where icepoint is 328. This covers a greater range of colder weather.
 gorem celcius fahrenht degH328 Rankine12 Gorem120 360 370 380 390 400 410 420 430 440 450 460 465.5 470 480 560 -33 -27 -20 -13 -7 0 7 13 20 27 33 37.0 40 47 100 -28 -16 -4 8 20 32 44 56 68 80 92 98.6 104 116 212 288 296 304 312 320 328 336 344 352 360 368 372.4 376 384 448 300 310 320 330 340 350 360 370 380 390 3V0 3V6.7 3 400 480 300 310 320 330 340 350 360 370 380 390 3V0 3V5:6 3 400 480
Rankine12 is degrees Rankine, in base 12. This is where the scale derives from.
Gorem120 is Gorems, in base 120. It preserves two places of Rankine12.
The degH328 refers to [h] bp = ip + 120, and [328] ip = 328. H30 and H40 are aslo used.
Note that decimal isotherms, eg 410, 420, 430, ... are drawn on maps more often than non-decimal ones, eg 415, 422. Making the measures fall in the same hundred makes for X00 = cold, X99 = hot. cf Kelvins, where 270 is cold, while 330 is hot.
gravity *
The conversion factor between the weight of mass, and its notional force.
metre/second² Description The PBSA value, 4pi / 1.296 The acceleration at Brisbane. [225/7 ft/s²] adopted for imperial SWS. The TILF value, as (1/0.102) metres / second sq Acceleration at Paris, taken as standard gravity The Etu value, taken at 32.175 UI ft/s².
greek fractions *
A system where one quotes proportion: such as x:y as 1944:2000. The ancient Greeks were certianly aware of sumerian and egyptian fractions
Gross and Net Units *
A system of larger units designed so that after shrinkage, the correct unit would remain. One might note, eg
Measure Gross hundred Net Notes 124 120 fish 496 480 sheets of paper (496 rounded to 500.) 14 lbs 8 lbs meat: 1 stone animal = 8 lbs sellable meat 13 12 Baker's measure 21 20 score = 20 units
Note the US usage of gross and net tons of 2240 and 2000 lbs respectively, are not reflecting this, but refer to an alternate use of long vs short.
Guild-Units *
A trade-system used by people in a particular line of industry. The essential features of the system is that the denominations of the units are the same, but the implementations vary from country to country.
The units are meant to be self-standing, not directly tied to the native measures of the country.
See, for example, Apothecaries, Troy measures.
Gunter *
Among other things Gunter invented the surveyer's chain, and the decimal division of the four-pole chain into one hundred links.
To gunterise is to round to the nearest multiple of 33, zb 99 ft for 100 feet.

© 2003-2004 Wendy Krieger