A stone for lead of 12 lb.
A London stone of 12-1/2 lb., one-eighth of the true Cwt.
A stone for groceries of 8 lb.; and 13-1/2 stone to make a Cwt. of 108 lb.
And the ‘fotmal’ of lead is to be 6 stones of 12 lb. but less 2 lb., ‘which are 70 lb. making 5 stones.’
Here then we see, besides a 12 lb. stone for lead,
(a) The true Cwt. of 100 lb. divided into quarters and nails.
(b) A transitional Cwt. of 108 lb. in 13-1/2 old half-stones of 8 lb.
(c) A new Cwt. of 112 lb. in 8 stones of 14 lb.
The Cwt. (centena) of 108 lb. seems to have been preparatory to the Cwt. of 112 lb. mentioned in this Ordinance (if it be not a later interpolation) and established later by Edward III. It preserved, for a time, the ancient half-stone of 8 lb., but by the inconvenient process of making 13-1/2 of these as the Cwt.; probably to prepare the merchant for a new Cwt. of 112 lb. first in 14 stones of 8 lb. and then in 8 stones of 14 lb.
This is the Cwt. which has come down from Edward III to the present day, against which trade has had to struggle more or less successfully ever since, and which torments the schoolboy with sums in tons, cwts., qrs. and lb.