Modern equivalents of historical weights and measures are often very difficult to determine, and figures given here should be treated with caution.
According to the Oxford English Dictionary, the word "fother" (noun) is derived from: OE.
[2] According to the Tractatus de Ponderibus et Mensuris, a memorandum of Edward I (reigned 1272–1307), the load of metallic lead was 30 fotmals, 175 stone, or 2,100 Merchant pounds (approx.
But of every Fotmal there are abated Two Pound in the foresaid Multiplication, which are Sixty, which make Five Stone.
[3][4]In Derbyshire up to the 13th century a fother of lead is recorded of 1680 lbs or 15 long hundredweight (cwt.)
(1016 kg)[5] Miners of lead ore in Yorkshire in the late 17th century used a fodder of 3,808 pounds (1,727 kg), on the assumption that the ore when smelted weighed about 65% less (about 2240 lbs or one long ton).
[7][8] Fothers were not used in all districts; for example in the Mendip Hills and in Burnley, Lancashire, tons, hundredweights and pounds were used in the first half of the 17th century.
[2] Vivant-Léon Moissenet, a French mineralogist who studied and wrote about English mining in the mid 19th-century[9] stated that in Shropshire 200 lbs were added to each ton of concentrate at the smelt works to make a ton of 2,440 pounds (1,110 kg).
[2] By the early 19th century there was a vast multiplicity of local measurements of all types of goods, which a parliamentary report of 1820 made clear.
When the metallic lead finally came to be sold it was weighed precisely; its value was calculated to the nearest pound weight and the price adjusted accordingly.
In Northumberland in the 1820s, a fodder of dung or of lime was equal to a cartload pulled by two horses.