COTTON-SPINNING MACHINERY. 305 



and wound hard on them, and the traverse endwise of 

 the bobbins, diminishing in length with their increase of 

 diameter, gave conical ends to the rovings, making them 

 safely portable. From these considerations it was highly 

 important to transfer to the fly frame the like movements 

 for winding the rovings hard upon the bobbins, by uniting 

 the compression to that of twist, in rovings for the higher 

 numbers in spinning. 



In the tube frame the axes of the bobbins are horizontal, 

 and the pressure of the rovings upon their surfaces is 

 obtained by simple weights attached to the tube carriers. 

 But in the fly frame the bobbins are arranged vertically ; 

 so that the pressure must be given by means of springs 

 attached to the arms of the flyers, or by the centrifagal 

 force of weights revolving with the flyers and acting upon 

 the pressers. Now both of these plans of pressing the 

 rovings upon the bobbins are very clearly described in 

 the drawings and specifications of my said patent for these 

 improvements on the fly frames, as before mentioned ^ 

 notwithstanding which, we have since seen that some 

 six or eight (so-called) inventions have been patented for 

 various and very trivial changes in the forms and modes 

 of applying the springs, and the centrifugal force of 

 weights revolving with the arms of the flyers, to press 

 the rovings on the bobbins. These patents have led to 

 many legal contests, and afibrded gainful work for the 

 lawyers in seeking to award the honours and profits . 

 pertaining to such inventions. 



I come now to speak of the really valuable and beauti- 

 ful invention for controlling the differential motions of the 

 fly frame, made and patented by Mr. Henry Houldsworth. 

 Having already explained the complex nature of the con- 

 tinually varying rotations required to make the delivering, 

 twisting, and winding-on motions agree (when changes in 

 either are required) , and also that those motions had before 



