96 



M. Achille Cazin on Internal Work in Gases, 



Series V. (August 1867). 



Dry air. Glass reservoir B. Manometer with cylindrical en- 

 largement. 



^ = 3*89 atmospheres, jt? 2 = 0*54 atmosphere. Temperature 

 between 19° and 20°. 



f0=Os-15 

 |A = -2 mm 



t = ... 



2-9 



7-7 



12-9 



23 



53 



90 



+28 



-62 



-15 



+ 1 



+8 



+3 







re=o-i7 





2-7 



7 



144 



18-6 



54 



90 



+38 



-56 



-7 



+ 8 



+ 11 



+2 







J 0=0-20 

 U=+4 





2-9 



6-3 



9-8 



151 



54 



90 



+37 



-62 



-19 



-3 



+7 



+2 







f0 = 0-23 



\h = + \3 





29 



6-2 



10-9 



179 



53 



90 



+40 



-62 



-21 







+8 



+3 







The coordinates of the minimum of the curves are 



and 



A=~65 millims., £=4*5 seconds, in Series IV., 

 h= —62 millims., t=2'9 seconds, in Series V. 



Hence a result of the increase of the dimensions of the mano- 

 meter, as might be foreseen, is to lessen the variation of the 

 levels, without changing materially the values of h. We also see 

 that the curves of Series IV. rise more slowly from the minimum 

 than those of Series V. 



The differences which the curves present at their point of de- 

 parture are due to the presence of the tube a a 1 in Series V., as 

 we shall see in the following paragraph. It may be observed 

 that, the effect of this tube being to raise for an instant the curve 

 at its point of departure, it attains its minimum a little later; so 

 that our conclusion cannot be doubted. 



§ VII. Influence of the position of the tube which connects the re- 

 servoirs with the manometer. 



We shall see in what this influence consists in the following 

 series, which may be compared with Series I. These two series 

 only differ in that the manometer Q is put in communication with 

 the tube S (fig. 2) in Series I., and with the tube H' in Series VI. 

 Thus the tube of communication passes into the middle of the 

 side of the reservoir B in Series I., and very near to the large 

 stopcock, on the side of the reser.voir A, in Series VI. 



