A machine employed in spinning cotton and other fibrous mate-rials. It was invented by Crompton, in 1779, and was found to produce finer yarn than was spun by the machine previously in use. For producing fine threads, a process analogous to that performed with carded cotton, upon a common spinning wheel, and called stretching, is resorted to. In this operation, portions of yarn, several yards long, are forcibly stretched in the direction of their length, with a view to elongate and reduce those parts of the yarn which have a greater diameter, and are less twisted than the other parts, so that the size and twist of the thread may become uniform throughout. To effect the process of stretching, the spindles are mounted upon a carriage, which is moved backwards or forwards across the floor, receding when the threads are to be stretched, and returning when they are to be wound up. The yarn produced by mill spinning is more perfect than any other, and is employed in the fabrication of the finest articles. The sewing thread, spun by mules, is a combination of two, four, or six threads. Threads have been produced of such fineness, that a pound of cotton has been calculated to reach 1G7 miles.

See Cotton and Spinning.