Ml 'I'll. in FOR in 'II IRMINING RESIMRATOR^ IMIIW'i.i. IN WW 





The bell is counterpoised by means of a weight. In the original Ti 

 spirometer an automatic adjustmenl permitted water in aim. nut equal 

 to the water displaced by the bell to flow Erom the spiromi tinder 



int. * a counterpoise cylinder as the bell ascended out of the wal 



Pig. 179. TI 



The bell, being heavier ou1 of water than when it is immersed, 



ingly counterpoised in any position, although Car] hown that 



this refill. 'in. 'nt is ann< y. An opening in I spiromi 



permits the insertion n\' a rubl pper, through which are passed a 



thermometer, a water manometer, and a si with t r drav 



