The “take-up” in twisting threads together is a factor of very great importance in the manufacture of every textile material. The manufacturer who considers this matter so trivial that he makes no allowance for it in his calculations will undoubtedly suffer pecuniary loss. Since many lines of textile work at the present day are cut very keen, the thin fringe of profit which the manufacturer imagines himself to be making may actually have assumed a negative value entirely in consequence of this seeming trifle. The fact that the elementary rule usually employed in the estimation of the size number of a twist takes no account of any contraction which may arise in the process of twisting fosters the idea that this quantity is negligible.