In India the gallon of canteen-spirit, rum or arrack, is reckoned as 48 drams, each 1/8 bottle or 3-1/3 fluid ounces.
The Imperial gallon, as 10 lb. of water = 160 fluid ounces, each of 437-1/2 grains of water at standard temperature.
Its eighth part, the Pint, contains 20 ounces weight or 20 fluid-ounces measure. It is so divided on druggists’ glass measures. The fluid ounce is divided into 8 fluid drachms, each of 60 minims, approximately fluid grains.
In the United States, where the old wine-gallon of 231 cubic inches is retained, the old wine-pint of 16 fluid ounces is used. 231 c.i. × 252·458 (grains of water in 1 c.i.) gives—
58,317·8 grains for the gallon 7,289·7 „ „ „ pint 455·6 „ „ „ ounce
The fluid ounce is divided as in England into 8 fluid drachms, of 60 minims.
------------------------------------------------------------------------
At some time before the Norman Conquest the Marc of Cologne was brought to England, probably only as the mint-standard of the later English kings, for the 16-ounce Roman pound was already long-established as the commercial weight.
The standard of the Cologne marc has never varied much.
Its mean weight = 3608 grains; when doubled it made a pound = 7216 grains, with an ounce = 451 grains. This pound is almost identical with the greater rotl of Al-Mamūn, 1/100 of the cantar = 102·92 lb.; and the old Prussian pound of Cologne standard was 1/100 of the Prussian centner = 103·11 lb.
The Norman Conquest made no change; the Saxon pound became the Tower pound, the King’s treasury or mint being in the Tower of London. The Tower pound of standard silver was coined into 240 silver pennies, which, at 22-1/2 grains, their weight down to the time of Edward III, gives 5400 grains for the pound and 450 grains for the ounce. An actual weight = 5404 grains was found in the Pyx chamber in 1842.
The shilling, of 12 pence, was until Tudor times only money of account. But it was also a weight of account, the pound being either 12 ounces of 20 pennyweight, or 20 shillings of 12 pennyweight.
‘When a quarter of wheat is sold for 12 pence, the wastel-bread of a farthing shall weigh 6 li. and 16 s. But bread cocket of a farthing shall weigh more by 2 s.’ (Assize of Bread, 51 Henry III.) That is, the farthing loaf shall weigh 6-16/20 Tower lb. = 5-1/4 averdepois lb., and the second sort 24 dwt. or 1-1/5 Tower ounce more.