A Calorimeter for the Human Body. 



235 



minute for the two; nearly the whole of the air in the chamber 

 would be carried through the two agitators every two minutes.* The 

 number of revolutions of the fans recorded by counters amounts 

 together to two or three hundred thousand per hour. 



The motor power for working the fans is obtained from the wires 

 used for the electric light of the laboratory, and exerted through two 

 small dynamos one for each agitator, while the action of either one 

 or the other can be regulated by a carbon-resistance. 



* The resistance caused by the ice, and a rose jet on the track from the lower 

 agitator, would probably reduce the draught to some little extent j no doubt, how- 

 ever, that the air is very thoroughly mixed inside the chamber. 



