A dictionary entry from Knight's New Mechanical Dictionary on hat blocking machines, which shape the felt hat body into brim and crown. It traces the history from D. Beard's 1816 patent through W. A. Fenn's 1857 roller machine to R. Eickemeyer's corrugation stretcher, then describes how the stretching and banding (blocking) machines work. Illustrated with figures of the stretcher, its head with levers, and three positions of the banding machine.