Dictionary entry from Knight's American Mechanical Dictionary describing the bobbin and fly frame, the roving machine of cotton manufacture that draws and twists sliver and winds the roving onto bobbins. It explains the flyer, spindle and bobbin motions, the cone-pulley speed compensation, the copping-rail traverse, and the difference between coarse (first) and fine (second) frames, with a quotation from Tomlinson and twist and speed figures. An engraved cross-section (Fig. 751) is keyed with lettered and numbered parts.