-: 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

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	cu in	gr / cu in	explanation
G0 - 1818	276.48	253.1828	The intent here was 1000 oz per cubic foot [never legal]
GM -	276.8	252.891	The conversion by 10 lb metric water
GA -	277.200	252.525	UK gallon = 1.2 US gallon exactly = 231*6/5.
G1 - 1824	277.274	252.4578	The gallon as implemented on 1824 measures
G2 - 1898	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	Indirect	Rule N
0	-	m permeability	e permittivity	-20	-10
11	mjar	C magn. cap	C capacitance	-9	1
11	mmic	L inductance	-	-9	1
110	Gs	B flux density	D flux density	100	110
110	Oe	H magn. field	E ele. field	120	120
121	Gb	U magn. potential	V elect potential	131	131
121	Bi	Y ampere current	-	131	131
132	Mx	FI magnetic flux	PSI elect flux	122	132
132	Fr	P magnetic charge	Q electric charge	122	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.
3.146 260 702 28	20 / polar
3.150 000 000 000	typical value for this value
3.152 161 253 53	value in nature, on pi*eq / polar
6 356 752.314 1	polar: polar radius in metres
6 378 137.000 0	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	360	370	380	390	400	410	420	430	440	450	460	465.5	470	480	560
celcius	-33	-27	-20	-13	-7	0	7	13	20	27	33	37.0	40	47	100
fahrenht	-28	-16	-4	8	20	32	44	56	68	80	92	98.6	104	116	212
degH328	288	296	304	312	320	328	336	344	352	360	368	372.4	376	384	448
Rankine12	300	310	320	330	340	350	360	370	380	390	3V0	3V6.7	3E0	400	480
Gorem120	300	310	320	330	340	350	360	370	380	390	3V0	3V5:6	3E0	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
9.696 273 622	The PBSA value, 4pi / 1.296
9.791 5	The acceleration at Brisbane.
9.797 142 857 14	[225/7 ft/s²] adopted for imperial SWS.
9.803 921 568 63	The TILF value, as (1/0.102) metres / second sq
9.806 65	Acceleration at Paris, taken as standard gravity
9.806 94	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	Net	Notes
hundred	124	120	fish
ream	496	480	sheets of paper (496 rounded to 500.)
stone	14 lbs	8 lbs	meat: 1 stone animal = 8 lbs sellable meat
dozen	13	12	Baker's measure
score	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.