1839 A. Ure 1165 The hopper b is attached to the upper frame, has its bottom concentric with the rasp-drum, and nearly in contact with it.
1924 A. J. Wallis-Tayler (rev. ed.) xv. 306 The rasp-drum is rotated at a speed of from 700 to 800 revolutions per minute, and is capable of reducing from 12½ to 15 tons of roots into pulp per day.