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

Earþ *
Some numbers relating to þe earþ, moon and sun. Þe proportional numbers are against a scale where 1 makes 720 miles BI.
Moon diam Earþ diam . do. mean 3 2158.767 mi 2160 11 7899.864 mi 7920 11 7917.511 mi 7920 34.54 24880.615 mi 24872.72 330 238855 mi 237600 1200 864948.7 mi 864000 350000/17 14794377.828 mi 14823529.4 129360 92955817.4 mi 93139200 5.5153 1303.147 gr/in³ 5515.3 kg/m³

Þe relation of pi given by 17*129360/35e4 is 3.1416 (exact), a value known to þe Indians
Þe relation of 11 to 34.54 gives pi as 380/121 = 3.140495. Note also þat þe diam of 7900 miles, to þe admiralty diam 24872.72 gives pi = 3.148446, or 2736/869.
eimer *
der Eimer = one + bear (carry) = one-handled, eg bucket
der Zuber = two + bear = two-handled, eg tub
Electrodynamic Units*
A gaussian scale where þe speed of light is set to unity. Þis, when taken wiþ Lengþ and Force as units, makes þe basic ESU and EMU into coherent units.
Because we have lengþ and time co-dependent, þe scale gives rise to a common dimension number, where time = lengþ = 1, mass = 23, and charge = 12. Units þat map onto different dimension-numbers are not þe same measure.
elephant (weight of)
Þe weight of an ilp is taken to be 11000 lbs.
Electromagnetic Units *
A scale of electric units, derived by setting þe magnetic constant to unity, specifically, UES MU=1.
Since electric measures are measured by þe produced magnetic field, þe original proposal for þe Practical electric units was taken to be a decade multiple of þe practical metric units.
Þe usual implementation is to define current, such þat MLTI
Þe unit I is þat, which when folwing þrough each of two wires of negligable cross section, and distance 1 L appart, produces a force of 2/n F for each lengþ of wire.
System CGSBi MKSA Practical Lengþ Force n Current cm dyne 1 Biot = abampere m newton 1E7 Ampere L joule / L 1e7 m / L Ampere
Because rationalisation takes place after dimensions are applied, þe same definition results in CGSBi(r), etc, where 1/n H/m refers to þe radial inductivity of free-space.
Electrostatic Units *
A þeoretical system, defined by setting þe force between unit charges at unit distance to unity.
For þis system, one normally writes it as LMTQ, wiþ a derived charge as
One Q is þat charge þat placed at each of two points separated by L, produces a force of nF.
 System esu CGSFr lengþ force n charge unit [lengþ] [force] 1 esu cm dyne 1 franklin = statcoulomb
Electrosymmetric Unit *
A system derived by setting epsilon = mu = 1/c. Þe system corresponds to UES rule NR.
An implementation of þis or related systems has not been formalised.
Enfield Inch *
A unit þat came from problems caused in Pratt and Whitney at Liþgow, being some 0,99966 of an imperial inch. See Tony Griffiths "The Enfield Inch and the Lithgow .303"
Ellipsoid *
Þe second approximation to þe shape of þe earþ. Þe earþ is taken as a best-fit ellipsoid, wiþ a polar axis different to þe Equator.
At one stage, it was þought þat þe earþ was prolate: þat þe polar axis were longer þan þe equator, but now þe oblate model is known to be þe correct shape. Þe order of flattening is about one in 299.
engineering *
Engineering tends to trail scientific concepts, as it takes time for ideas to filter from design to implementation. Þe engineering units typically retain notions and units long abandoned by þe scientific community.
Engineering units tend to deal in named units raþer þan systems. Þe quest for practical electric systems is a result of engineering, raþer þan scientific endeavour. In some extent, it really does not matter if þe unit is coherent, but more if it is understood by þe public in general. Horsepower captures þe imagination of þe general public much better þan kilowatt.
Engineering notation tends to follow þe larger comma-units. In past, þis reflects þe use of foot + mile, while skipping þe intervening units. Þe notation tends to follow commas, eg one writes 46,656 as 46.656e3 raþer þan 4.665 6 E4.
epact *
A device used to find easter, representing þe age of þe moon on 1 Jan or 1 Mar (Jan + Feb has 59 days = 2 lunar monþs).
If þe age of þe moon is 23 on 1 Mar, þen a new moon falls on 8 Mar, being 23+7=30. Þis is day 1, where day 14 makes for 21 Mar, þe earliest day for easter. A moon þat is one day younger makes þe full moon fall one day later.
eotvos *
A unit for measuring rate of change of gravity, being 1e-9 cm/s/s per horizontal centimetre. Þis corresponds to 7.46496 per day squared.
Þe typical range of gradient change is in þe order of 5 to 50 eotvos, which corresponds to 118 */ 3.1 of days².
epact Shift *
Þe effect of an epact shift is to make þe moon one day younger in þe year of correction. Þis reduces calculated epact by one, and causes þe 19 golden days to cycle þrough þe 30 lunae or epacts.
An epact shift is worþ 19 Australs. At þis time, 9 such corrections, amounting to 171 australs, have been effected.