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-- 20’s cotton equals 30’s worsted, (20 × 840)/560 = 30’s 20’s cotton equals 56’s linen, 300 : 840 :: 20’s : 56’s. 20’s cotton equals 20’s silk. 20’s English equals 16·93’s French. 1·18 : 1 :: 20’s : _x_ _x_ = (1 × 20)/1·181 = 16·93 _Double Yarns (Cotton)._--Two-fold yarns are numbered according to the single yarn counts--thus, 2/80’s = two ends of 80’s twined together, which would wrap 40’s. Actually, to make the resultant count 40’s, the single yarn should be finer than 80’s, because the twist put in the folded yarn contracts it in length and causes the two-fold to be really coarser than would appear. However, neglecting this, suppose we twine one end of 40’s and one of 20’s, the counts would not be 15’s, as a first glance would indicate, but 13·33. This can be proved by taking the weight of a lea of 40 = 25 grains, and of 20’s = 50 grains; total, 75. 75 divided into 1000 gives the counts as 13-1/3. Another rule is, multiply the two counts and divide by their sum-- (40 × 20)/(40 + 20) = 800/60 = 13-1/3 3/300’s = 100’s.