COTTON-SPINNING MACHINERY. 301 



well established to require any aid from my pen. I might 

 also mention other able and distinguished mechanics who 

 contributed to the improvements in building these frames ; 

 hut it were no easy task to assign to each his true share 

 in them. Besides^ the '' differential motions " were still 

 so imperfect in the principle of action as to call for other 

 and more essential changes to secure the correctness re- 

 quired for safe working. 



This defective state of the bobbin and fly frame had led 

 to the invention of a substitute for it, in which the bobbins 

 were turned (in taking up the rovings) by surface friction 

 instead of by central action. The operations of this new 

 roving-frame are as follows^ viz. : — 



In place of using the throttle-spindle and flyers, the 

 rovings are conducted to and placed upon the bobbins by 

 means of revolving tubes (arranged in a line with the roller- 

 beam), through which the rovings pass, and are compressed 

 by being twisted and untivisted before they are placed 

 upon the bobbins. A range of fluted cylinders, the length 

 of the bobbins, are placed along a driving-shaft (the length 

 of the roller-beam) ; and the bobbins, being mounted upon 

 the cylinders (under suitable pressure) , are carried round 

 by the simple contact-friction of their surfaces. Thus the 

 rovings are duly taken up and wound upon the bobbins 

 as they pass from the roller-beam through the twisting- 

 tubes to the surface of the bobbins. The cylinder- shaft is 

 geared (by wheels or pulleys) to the axis of the front 

 rollers, so as to make their speeds inversely as the diameters 

 of the cylinders and delivering-roUers. Thus the equable 

 surface-motion is secured for taking up the rovings, at 

 whatever speed they may be given out from the roller- 

 beam. A steel presser is placed just opposite to the nose- 

 end of the tube ; the rovings pass through a hole in the 

 presser as they leave the tubes, and are firmly pressed 

 upon the bobbins in being wound upon them. 



