cloth is damp, warm water and soaps being used to facilitate it. There appears to be no limit to the felting capacity of wool or the shrinkage which may accompany it.
Fig. 28.—Hot-air Drying and Tentering Machine.
By the most primitive methods the fulling was done in tubs under the pressure of the feet, a tedious process, requiring several days. In the early days of mechanical manufacture the cloths, after boiling or scouring to remove the oil, were folded in laps, hammered, refolded, and again hammered five or six times, until the fibers had matted and shrunk to the desired size. At a later period there followed a primitive method of automatic fulling, in a milling trough, with "stocks," which were two heavy wooden mallets, lifted in succession by cogs fixed on the axis of a water-wheel. These hammers would make from thirty to forty blows a minute, and the process was repeated four or five times, with intermediate soapings and rinsings, occupying a day to complete it.
The fulling-mill with rollers is an American invention, that of John Dyer, whose patent bears date 1833. The invention of the double crankshaft fulling-mill was also of American origin, Levi Osborne's first machine, made in 1804, being the first of a series of valuable machines on that principle. By the use of the new methods of fulling, the cloth, after saturation with soap and water, is passed between two vertical rollers in a twisted condition, the pressure applied causing it to shrink in the direction of the weft. As the cloth passes through these rollers its progress is interrupted at intervals, and it is held in a trough
