Although the 1/4-inch scale is mostly used for calculating warps in Lancashire, we give an example of a calculation with the Bolton reed. To get the number of ends, multiply the reed counts by the width of your warp in the reed, and by 1·6495—thus, Bolton 36’s, 39 inches in the reed, would give 2238 ends. The calculation is then proceeded with in the ordinary manner. In the Scotch ell standard system, the dimensions of the cloth before-mentioned would be 36 inches wide, 36 yards long, 1100 reed, 11-1/2 shots to the glass, yarns 30’s/36’s. To calculate the weight of warp, add six per cent. to the 36 inches, making it 38 inches wide in the reed. If there are 1100 splits on 37 inches, then the number on 38 inches will be proportional.
(1100 × 38)/37 = 1130.
Multiply by 2, as it is always understood that there are two ends in a split, and we get 2260 ends. The calculation is then continued in the usual way.
(2260 × 38)/(840 × 30) = 3·407lb.
Weft.—— The meaning of shots on the glass refers to a counting glass used in Glasgow district, one two-hundredth part of a yard in width; 11-1/2 shots will then give 11-1/2 × 200 = 2300 picks in a yard.
(2300 × 37-1/2 inches wide)/(36’s × 36 inches to the yard × 840) = 2·85lb.
If required to be left in hank, omit to divide by the counts in each case. In other materials, the length of the hank varies, and, in the case of single worsted, we should have divided in the previous calculations by 560 instead of 840, in linen by 300, or in single silk by 840.
Warping and Sizing Calculations.
In getting an order passed through a weaving shed the first point, after calculating the particulars for each piece or cut, is to get the length for warping and sizing. In the case of an order for 3750 pieces of the before-mentioned dimensions, the total length of warp is calculated thus—38 yards for one piece × 3750 = 142,500 yards, allowing nothing for waste in length, as the tension on the yarn in process will stretch it sufficiently to allow for that, and perhaps a little more. At the warping mill the length is taken in wraps of 3564 yards, subdivided into teeth of 27 yards. In this case, four wraps or 14,256 yards would be taken to a set of back beams; therefore, this order would be run in ten separate sets.
The number of back beams for the sizing machine is proportioned to the capacity of the warping mill—say five beams, the length on each beam must be 14,256 yards, and the total number of ends on the beams equal to the ends in the piece—say 5 at 456 each = 2280.