To prove this is correct take a piece 20 inches wide, 102 yards long, 93 threads per inch both in warp and weft of 45’s yarns.
The weight of this sample piece will be—
20 × 102 × 93840 × 45 = 5 lbs. of twist;
and as there is the same weight of weft, the total weight of the piece will be 10 lbs.
Now calculate the weight of a piece of the same length and width with 62 threads per inch of 20’s yarns:—
20 × 102 × 62840 × 20 = 7½ lbs. of twist;
and with the same quantity of weft, the total weight of the piece will be 15 lbs.
This proves the calculation to be correct so far as altering the weight goes.
To see if both cloths are of the same firmness, the table of diameters may be referred to. It will there be seen that a plain cloth with 93 threads per inch of 45’s yarn is “perfect,” and also that the altered cloth with 62 threads of 20’s is equally perfect.
It thus proves the principle of the calculation to be correct.