No coin nor oath required. For personal study only.
Comparative tests were made with specimens in which the stitching thread was broken. It was found that the shuttlestitch seam was weakened much more than the double-locked stitch, and the pulling out of the threads in the former stitch caused the seam to give way before the fabric was torn. This is objectionable, because the hole thus produced must be sewed up to prevent it becoming larger. With the double-locked stitched seam, however, a broken stitch does not produce a hole, as each loose end becomes securely locked and the seam remains as strong as it was originally.
Other tests were made to show the stretching qualities of the two kinds o.f stitching. The results of these tests show that the double-locked stitch is more elastic, stronger, and less likely to be injured by tension along the seam than the shuttle method of stitching.
The results of this investigation show that seams produced by the double-locked stitch are superior to the shuttle stitch. No attempt was made to compare the two types o.f stitching in other respects, such as production capacity of the two types of machines; cost of production, with special reference to consumption of time, thread, and fabric ; deterioration due to wear, etc.
๐ SIMILAR VOLUMES
Two iicw types of silicon iron ])u~iips Itnvc rcccntly been de\dopcd by the writer :it tlic works of Gnt.lirie & CO., Cltemic:tl lhginccrs, Accrington, Englnnil, to e I FIU. 1 Mcfhorf o/ wspentlixg silicon iron impeUer deal with the rcqiiireiiieiits spccilicd by Iiirgc clieinicnl muiiufiicturers. Fo