272 



M. Achille Cazin on Internal Work in Gases. 



and (p. 117) that the binomial of dilatation at constant pressure is 



1 + 100 * = \l-38 



•37099 under the pressure of 760 millims. 



By means of these data I calculated the following Table, in 

 which column p (1) gives the observed pressures, column p (2) 

 gives the pressures calculated from formula (6), taking 0=1*6; 

 column p (3) gives the pressures calculated according to the same 

 formula, taking «=1'9. It may be seen that the numbers of 

 column p (3) all diverge in the same direction from the numbers 

 of column p (1), whilst those of column p (2) diverge at first in 

 one direction, then in the opposite ; which justifies the use of 

 fi=l-6:— 



V. 



T. 



*(1). 



J»P). 



p{\)-p{2\ 



p{3). 



*(l)-*(3). 



cub. met. 





millims. 



millims. 



millims. 



millims. 



millims. 



0-69333 



373 



760 



756 



+ 4 



755 



+ 5 



0-38307 



273 



1000 



996 



+ 4 







0-20779 



373 



2520 



2508 



+ 12 



2504 



+ 16 



015008 



273 



2520 



2510 



+ 10 







010437 



273 



3589 



3578 



+ 11 







010437 



373 



4974 



4955 



+ 19 



4950 



+ 24 



003831 



273 



9226 



9257 



- 31 







0-01915 



273 



16705 



16961 



-256 



16380 



+325 



Between zero and 100°, one atmosphere and twelve atmospheres, 

 the values of p (2) are sufficiently near ; but at twenty-two atmo- 

 spheres the difference p (1) — p (2) is large enough to make the 

 formula of Mr. Rankine not very exact ; but I thought it neces- 

 sary to use it provisionally, with the modification relative to a 

 which I have indicated. In order to establish a more satisfac- 

 tory empirical formula, some data relative to high temperatures 

 would be necessary, which are totally wanting. 



Numerical application of formula (7) : — 



= 0-10871 cub. m. 

 = 052056 „ 



The ratio of these two numbers is that of the reservoirs of my 

 ultimate apparatus. 



I consider one kilogramme of carbonic acid at 10°, passing 

 from volume v l to volume v\ in the conditions of the problem 

 already enunciated : — 



1 



A = 



425 



a =1-6, 

 p = 10334, 



