H YDR KINETICS. 



151 



FIG. 90. 



264. The Reac- 

 tion Wheel. The 



reaction wheel is well 

 illustrated by Barker's 

 Mill, represented in Fig. 

 91. It consists essential- 

 ly of a vertical tube con- 

 necting with horizontal 

 tubular arms at the bot- 

 tom. The ends of these 

 arms are bent in the 

 same direction, and are 

 open at their ends. The 

 apparatus is supported 

 on a pivot so as to move 

 freely. Water is poured 

 into the upper end of the 

 vertical cylinder, and es- 

 capes through the open- 

 ings a and I, at the 



wheel, against a few float 

 boards, which are more or 

 less submerged, and thus 

 acts by the force of the 

 current. 



Note. In point of efficien- 

 cy, these wheels rank in the 

 order above given, utilizing 

 from 80 to 25 per cent, of the 

 total energy of the stream. 



FIG. 91. 



bent ends of the arms. The wheel revolves in a direction 



