A dictionary entry from Knight's American Mechanical Dictionary describing the slubbing-billy and slubbing machines used to give wool cardings a light twist before spinning. It explains the billy-gate carriage, spindles, leather apron, billy-roller and clasp, and how the carriage motion draws out and twists the rovings. It also covers the condenser form of slubbing machine and relates the machine to Hargreaves's spinning-jenny and the mule. One engraving (Fig. 5211) shows a slubbing-billy.