340 A BRIEF MEMOIR 



steam-engine supplied power for the mule spin- 

 ner, which was soon generally embraced instead 

 of Kelly's appHcation of water power, the use 

 of which can only be local. The mule spinning 

 now took the lead, and became important and 

 extensive. The profits being very considerable 

 the increase was rapid. It was not until 1793 

 that any attempts were made in spinning fine 

 yarns, say from 100 hanks upwards, by power, 

 when I observed the process very carefully. 

 The rollers, according to the fineness of the 

 thread, would only admit of a certain velocity 

 per minute, for instance, with 200'''* the rollers 

 could only go at the rate of 25 or 26 per minute, 

 and the spindle about 1,200. But when the 

 rollers ceased to move, then the spindle was 

 accelerated by the spinner to nearly double its 

 former speed. In what manner the acceleration 

 of the speed of the spindle might be effected by 

 machinery without the aid of the spinner, was 

 suggested to me, by observing in Mr. Watt's 

 steam engine, that one revolution of the beam 

 (if I may use the expression) acting upon the 

 fly wheel by means of the sun and planet wheel 

 produced a double velocity. The difficulty 

 however of making the necessary apparatus at 

 that time, induced me to use the more compli- 

 cated method of four wheels of unequal sizes 

 for producing the same effect. The description 



