Example.—How many grains should 120 yards of 40’s yarn weigh?
1000 grains40’s counts = 25 grains.
When testing the counts of cops, it is usual to wrap two, three, or four cops, in order to arrive at a more satisfactory test.
If two leas, or two-sevenths of a hank, are weighed, the counts can be obtained by dividing the weight into 2000 grains, or two-sevenths of 1 lb. If three leas, or 360 yards, are weighed, divide the weight into 3000 grains, and the result is the counts. If 480 yards are weighed, the dividend is 4000; if 600 yards, or five leas, are weighed, the dividend will be 5000; if six leas, or 720 yards, are weighed, the dividend is 6000; and when seven leas, or one hank, is weighed, the dividend will be 7000 grains, or 1 lb.
As it takes a considerable time to take 120 yards of weft out of a piece, a shorter length is often weighed and the counts found therefrom. A balance is extensively used which registers the counts when twenty yards of yarn are put upon the pointer. This is a very useful, though not always accurate, method.
When any odd length of yarn is weighed, the counts may be obtained by proportion, thus—
If 34 yards of yarn have been found to weigh 8 grains, what count is it?
The yards in 1 lb. can first be found as follows:—
grains
grains