THE ATMOSPHERE. 



densing syringe precisely the same relation which the air-pump 

 bears to the exhausting syringe. It consists of one or two 

 condensing syringes, mounted so as to be conveniently worked by 

 a winch, and communicating with a strong reservoir, which is 

 fastened down upon a plate, so as to be maintained in air-tight 

 contact with it, notwithstanding the bursting pressure of air con- 

 densed within it. By the operation of syringes, volumes of air 

 corresponding to their magnitude are forced continually into the 

 reservoir, which becomes therefore filled with an atmosphere pro- 

 portionally more dense than the external air. 



112 



