106 



MECHANICS. 



DYNAMOMETER FOR ROTARY MOTION. 



All these dynamometers apply only to simple, onwar^ 

 draught, as in plowing, drawing wagons, harrowing, etc. 

 There is another, represented in fig. 115, of very ingenious 

 but complex construction, which shows the force required, 

 in working any rotary machine, such as thrashers, straw-, 

 cutters, and mills, and showing, at the same time, the ve-; 

 locity, and re'cording the number of revolutions made. 



The whole machine is supported by a cast-iron framcr 



Fi-. 115. 



Dytuimomctcr for measuring the force and velocity of thrashing-machines. 



work, on four small wheels with ilanges, like the wheels of 

 rail-cars, that it may be conveniently run up on a temporary 

 rail-way to the thrashing or other machine to be tried. 



The band-wheel /*, on the shaft e, is connected with the 

 machine under trial, and the force is supposed, in this in- 

 stance, to be applied by hand to the handle a, on the fly- 

 wheel. 



