132 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. 



Fig. 618. 



The manner of using the instrument is this : After hav- 

 ing driven all the ether into the ball b, by the heat of the 

 hand, it is to be placed in an open window, or out of doors, 

 with the ball b so situated as that the surface of the liquid 



