Yarn Calculations.
The fineness of cotton yarn is indicated by the counts (otherwise numbers or grist). The counts refer to the number of hanks in a pound (avoirdupois). The cotton hank is always 840 yards; and, therefore, if we speak of 10’s, we refer to yarn of which 10 hanks or 8400 yards weigh one pound; or in referring to 36’s, of that which 36 × 840 or 30,240 yards weigh one pound. This applies to either twist or weft. The cotton yarn measure is—
120 yards = 1 lea.
7 leas or 840 yards = 1 hank.
and the cotton yarn weight is peculiar, being an avoirdupois pound divided into pennyweights and ounces as in the troy weight.
24 grains = 1 pennyweight.
437-1/2 grains = 18-11/48 pennyweights = 1 ounce.
7000 grains = 16 ounces = 1 lb.