DYNAMOMETER FOR ROTARY MOTION. 129 



cisely similar to the cylinder of oil described in Fig. 

 99. Another part is the pendulum, j9, with the wheel, 

 r, which measures the time. 



The use of this instrument has been already attend- 

 ed with some important results in detecting the great 

 amount of friction existing in some thrashing-machines 

 of high reputation, which has been found to amount, 

 in certain cases, to more than one half of the whole 

 power applied. It is only by detecting so great a 

 waste that we are enabled to take measures for its 

 prevention. 



F2 



