The method adopted by thread manufacturers in winding cotton on ordinary reels is to use a spooling machine. Wield's spooling machine has been very successful, and winds a number of spools simultaneously. Each bobbin is fixed between two conical spindles that are driven by gearing. The cotton is guided by steel guides, threaded to correspond with the pitch of the screws formed by the thread on the spool. These guides have a reciprocal horizontal traverse equal to the length of the spool, and gradually increasing as the surface upon which the thread is wound increases; this increase arises from the bevel on the flanges of the spools. This movement is obtained from a fine-pitched screw on a roller, with which two half nuts alternately engage, one on each side of its centre. As these are thrown into gear, they give a traverse to the guide rail in each direction, and the period of engagement determines the length of the traverse. In winding, the reels fall into position from a trough or reseivoir on to a plate, which rises so as to bring the spool between the open spindles. These close, immediately begin to revolve, and the guide rail begins its horizontal motions. The thread is passed through a spring tension clip, which holds it tight.

When the required length of thread is wound on, winding automatically ceases, and a knife, placed in an arm, descends and cuts a nick in one end of each spool; the thread is drawn into this nick and over another knife and cut. The spindles then open, and the spools fall down a shoot. Another set of spools is then fed as described, and the ends of the thread are so held that, immediately the spindles begin to revolve, the ends are drawn on to the spools. Twenty-six gross of spools, each spool containing 200 yd. of thread, can be wound by a machine in ten and a-half hours.