1. General View of the Imperial System

The Imperial system of Weights and Measures rests on principles quite as rational and scientific as those of the Metric system, and it is much more practical.

All its series are derived from the English talent, a weight two-thirds of the Roman-Alexandrian talent which was derived from the royal cubit and foot of ancient Egypt.

The original system, of at least ten centuries ago, was as follows:

Length.—The foot was the measure of the side of a cubic vessel containing 1000 Roman ounces of water.

The furlong became at a very early period a length of 40 rods = 220 yards.

The mile, originally 5000 Roman feet, became 5000 English feet, divided into 8 road-furlongs.

Surface.—The acre was one-tenth of the square furlong.

Capacity.—The wine-bushel was the cubic foot, the measure of 1000 ounces of wine or water. 1/8 of it was the wine-gallon = 1728/8 or 216 cubic inches.

The corn-bushel was 1-1/4 cubic feet, the measure of 1000 oz. = 62-1/2 lb. of wheat; 1/8 of it was the corn-gallon = 270 c.i.

Weight.—The pound was 16 Roman ounces = 6992 grains. Its multiples were the 16-lb. stone, the wey of 16 stones, and the true cwt. of 100 lb.

This excellent system has become, after many disturbances, the Imperial system, only differing from the old English system in the following points:

1. The slight rise of the pound (by 8 grains) to 7000 grains.

2. The rise of the wine-gallon to 231 c.i. as now used in America.

3. The unification of the wine- and corn-gallons (the latter still used in America at the standard of 268·8 c.i.) in the Imperial gallon = 277-1/4 c.i. = 10 lb. water.

4. The fixing of the mile at 8 roods or field-furlongs of 220 yards.

5. The optional decimalisation of several series:

(a) Of the furlong at 10 chains, of the square furlong at 100 sq. chains, and of the acre at 10 sq. chains.

(b) Of weights by the 10-lb. gallon and the 100-lb. cental.

6. The disappearance of the Troy pound. The Troy ounce must shortly disappear; the 112-lb. cwt. and its stone-divisions are optional.

The Imperial Standards are now:

Length.—The Foot, approximately the side of a cubic vessel containing 1000 ounces of water. The yard of 3 feet or 36 inches.

The Furlong is 220 yards, either—

10 chains of 66 feet or 22 yards, or 40 rods of 5-1/2 yards.

The Mile is 8 furlongs = 1760 yards.

The Nautical mile is 1000 Olympic fathoms = 6080 feet or 2026-2/3 yards.

Surface.—The square furlong is 10 acres; the acre is 10 sq. chains, or 4840 sq. yards, and may be divided into 160 sq. rods.

Volume.—The cubic foot is approximately 1000 ounces of water, = 62-1/2 lb. The Ton-register is 100 cubic feet.

Weight.—The pound, of 7000 grains, is divided into 16 ounces of 437-1/2 grains.

The Gallon of water weighs 10 lb.

The Cental is 100 lb.

The Ton is 20 long Cwt. of 112 lb.

Capacity.—The Imperial gallon = 277-1/4 c.i. contains exactly 10 lb. of water, or approximately 8 lb. of wheat. It is divided into 8 pints containing 20 oz. of water or 16 oz. of wheat. The Bushel, of 8 gallons, contains 64 lb. of wheat.[^[58]] The Quarter is 8 bushels, which is approximately the quarter, either of a short ton, 20 centals, of wheat, or of a freight-ton of 40 cubic feet.

The principal units, foot, pound, gallon, are connected by their common origin in the talent of 1000 ounces of water. Corrections are needed for accuracy since the pound was increased in Elizabethan times by a little more than 1 per 1000 from its original Roman standard, and since the bushel and gallon were increased by 3 per cent. from the original corn-measure to the Imperial standard.

The co-related units, foot, furlong, acre, pound, gallon, are multiplied and divided by the factors found by long use to be the most convenient to the people. When no other influence determines the secondary units, the usual factor is 8, or its double, its half, its quarter.

Any unit may be decimalised for purposes of calculation, and several series have alternative decimal series. Thus—

Itinerary and Land measures were decimalised three centuries ago by the chain-series.

The Ton-register of 100 cubic feet, used throughout the world, has a complete decimal series of divisions.

The pound-gallon-cental series are fully decimalised, from the 100-lb. cental down to the septem, 1/1000 of a pound.

A decimal series of weights from the pound upwards is perfectly lawful. It may be confidently expected that it will before long replace for most purposes the stone and long-hundredweight series imposed in the fourteenth century, and fought against ever since.

Apothecaries’ weight, abolished by the Medical Council half a century ago, still lingers in the Board of Trade list of standards. Mint-weight is still on the Troy system. The half-crown is one grain less than an Imperial half-ounce. It may be hoped that it, and other silver coins, will before long be brought exactly to that standard. Already the bronze penny is one-third of the Imperial ounce.

Further improvements will be made. Some adjustment of the inconvenient 112-lb. hundredweight with the cental series, that of our ancient hundredweight, returned to us from America, will probably be effected. In the meantime we know that our system is progressive.

It may not have such a scientific appearance as that of the metric system. But we must not be dazzled by the word ‘scientific.’ Our system has its series related with sufficient exactness to have practically as much unity as the metric system; and it is convenient. Let us distinguish between science and pedantry.