420 Til K IRll I GA TION A GE. 



not be diverted from it. He made every size exactly similar to that 

 10- inch wheel upon which his experiments were made. He had 

 always the same number of guides and the same number of buckets. 

 The center of each curve was at exactly the same place, and the 

 radius of the curve was exactly proportional to the diameter of the 

 water-wheel. 



The capacity of each pattern was just one- third- more than that 

 of the pattern which was next below it in size. His 26^ in. wheel was 

 of just twice the diameter of the 13^ in. wheel, and the 6f in. wheel 

 was of just one-half its diameter, and so there was an accuracy of 

 proportion which was before unknown. If some of the designers of 

 our modern types of wheels, which are constructed on very compli- 

 "cated principles, had more of the common sense of James Leffel and 

 made fewer changes, there would be fewer disappointments. Even 

 the number of buckets in our wheels of to-day can not be changed 

 without altering the distribution of water in the draft-tube and the 

 percentage of the wheel. James Leffel, like few others, died when 

 his work was done. He left his well- developed invention in the hands 

 of able men, who appreciated it and knew how to sell water-wheels, 

 and the profits from it have exceeded $2,000,000. 



The greatest work done by James Leffel was the introduction of 

 the short-draft tube carrying the bridge-tree which supports the step 

 and shaft, he being the first to make use of this. It prepared the 

 way for the water-wheels of increased power and capacity which are 

 exclusively used at the present time. In these the draft-tube performs 

 the function of the Boyden diffuser and saves the momentum and 

 power that remains in the water after it has passed through the 

 wheel. Experiments recently tried by the writer on the same wheel, 

 first with and afterwards without a draft-tube, showed a difference in 

 power of 15 per cent, in favor of the draft- tube." 



