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.
Wrapping.
1’s are taken as the standard with 840 yards in 7000 grains, and a higher count means finer yarn; then 840 yards of, say 2’s, would weigh 3500 grains, or of 70’s, would weigh 100 grains. If we measure a hank of yarn, and find that it weighs 100 grains, then 7000, divided by 100, gives the counts. It is inconvenient in wrapping yarn to measure 840 yards, therefore a lea of 120 yards is taken as the standard length for 1’s, and also the proportionate weight = 1000 grains. Instead of taking 840 yards and 7000 grains it is usual, then, to take 120 yards and 1000 grains. A wrap reel is 1-1/2 yards in circumference, and, by revolving it 80 times, we can wind 120 yards from a cop placed in the machine. Suppose this lea of 120 yards weighs 25 grains, then 10000/25 = 40’s. Should less than a lea be taken, say 60 yards, then 500 grains must be the dividend. Generally, however, to obtain the counts of any yarn, 120 yards are weighed, and the weight, in grains, divided into 1000.
Having the Length and Counts given, to find the Weight.—9240 yards of 44’s weft = 9240 yards ÷ 840 = 11 hanks. In the given counts 44 hanks weigh 1 lb., then 11 hanks weigh 11/44 or 1/4 of a lb.
Counts of Silk, Worsted, Linen.—Single silk is counted same as cotton, except that in two-fold patent silk the actual wrapping is given—say, 30’s/2 in silk will wrap 30’s. In cotton, 2/30’s would wrap 15’s. The worsted hank is 560 yards. The linen “lea” is 300 yards. The French cotton standard is 1000 metres in 500 grammes—equivalent to 992·4 yards in 1 lb. Thus, 1·181’s in English would be 1’s in French. To transfer cotton measure to any other take the cotton count, proportion it inversely to the number of yards in the hanks, say—