Paper by Professor A. F. Barker of Leeds University, read at the Textile Institute's Autumnal Congress in 1915, on weaving delicate single warps of botany and crossbred wool with centre-shed tappet motions rather than open-shed tappets. It argues that centre-shed tappets reduce warp tension, thread breakage, heald wear and power consumption, and it explains cam design for 2/2 and 3/3 twill tappets, with diagrams, tachograph speed records and tables of power use and mending costs. The paper also covers Continental competition in twill and serge fabrics, and it ends with the discussion that followed.