368° Mr. Treadwell’s Description of a Machine, 
it should approach more nearly, in its revolutions, to those made 
by the flyer. Now the flyer is driven with a uniform velocity, and 
the filament also is delivered from the drawing-rollers with a 
uniform velocity. Suppose, then, that the circumference of the 
bobbin, when naked, be one foot, and that the surface of the 
drawing-rollers moves through one foot in two seconds, and that 
the flyer makes twenty revolutions in two seconds. ‘Then, that 
the yarn may be wound up, the bobbin must make nineteen revo- 
lutions in two seconds. When, however, the bobbin, by being 
filled with yarn, has a circumference of two feet, it is evident that 
it must make nineteen revolutions and a half in two seconds, that 
the same object may be accomplished, the velocities of the draw- 
ing-rollers and the flyer remaining constant. To provide for the 
required increase of velocity in the bobbin it is only necessary 
that the belt which passes from the drum 9f to the pulley 6f shall 
be of so slight tension that it may be made to slip, in some degree, 
by the pulling of the yarn itself upon the bobbin, from the constant 
tendency, by the flyer, to wind it up. 
For the purpose of spreading the yarn over the whole surface 
of the bobbin it is necessary that the bobbin should be moved, 
alternately, through a space equal to its length, in the direction 
of its axis. To accomplish this a collar is placed upon the 
spindle at 3g. This collar runs in a stud 4g, which stands upon 
the slide 5g; which slide can be moved in the direction of its 
length, its right end resting in a proper box on the frame 6e. 
Two chains or straps pass from buckles, on the slide 5g, seen in* 
fig. 14, over the top of the pulley 6g, in opposite directions, and 
are fastened to the periphery of the pulley on different sides of 
the same. Two other chains or straps, similar to those above 
described, pass from buckles on the slide or rod 7g, and are 
connected with the small pulley 8g. The pulleys 6g and 8g are 
