Great as have been the improvements in many matters in spindle structure, the drawing, the stretching and the twisting still remain fundamentally the same in principle as in the singing throstle of Arkwright and the steady mule of Crompton. And yet so great and rapid has been the advancement of inventions as to details and to meet the great demand, that the machinery of half a century ago has been almost entirely discarded and supplanted by different types. A great improvement on the spinning frame of the 18th century is the ring frame invented by Jenks. In this the spindles, arranged vertically in the frame, are driven by bands from a central cylinder, and project through apertures in a horizontal bar. A flanged ridge around each aperture forms a ring and affords a track for a little steel hoop called a traveller, which is sprung over the ring. The traveller guides the thread on to the spool. As the spindles revolve, the thread passing through the traveller revolves it rapidly, and the horizontal bar rising and falling has the effect of winding the yarn alternately and regularly upon the spools. The bobbins of the spindle frame were found not large enough to contain a sufficient amount of yarn to permit of a long continuous operation when the warp came to be applied, and besides there were occasional defects in the thread which could not be detected until it broke, if the yarn was used directly from the bobbins. So to save much time and trouble spooling machines were invented which wind the yarn from the bobbins holding 1200 to 1800 yards, to large spools, each holding 18,000 to 20,000 yards; and then by passing the yarn through fine slots in guides which lead to the spool, lumps or weak places, which would break the yarns at the guide, could at once be discovered and the yarn retied firmly, so that there would be no further breaking in the warper. After the yarn is finally spooled it is found that its surface is still rough and covered with fuzz. It is desirable, therefore, that it shall be smoothed out and be given somewhat of a lustre before weaving. These final operations are performed by the warping and dressing machines. In the warping machine the threads are drawn between rollers, the tension of which can be regulated, and then through a “reed,” a comb-shaped device which separates the threads, and then finally wound upon a large cylinder. In this machine a device is also arranged which operates to stop the machine at once if any thread is broken. When the cylinder is filled it is then taken to the dresser, which in its modern and useful form is known as the “slusher,” by which the yarns are drawn through hot starch, the superfluous starch squeezed out, and the yarns, kept separated all the time, dried by passing them around large drying cylinders, or through a closed box heated by steam pipes, and then wound upon the loom beam or cylinder.