306 Mr. W. C. Unwin on the Relations of Pressure, 



The following short table gives some values of t calculated 

 from p :- 





t 





p. 







Calculated by (7a). 



Observed. 



4-60 



272-7 



273 



91-98 



322-8 



323 



760-00 



3732 



373 



3581-2 



423-2 



423 



11689-0 



473-1 



473 



The following are the derivative expressions. A few values 

 are calculated from each and compared with the values very 

 laboriously calculated by Zeuner from Regnault's formula. 

 1 dp _ 21815 

 p dt " t 2 ' 25 



(8) 



_ (7-5030 -logp) : ' 





441-3 " ' " 



t. 



1 dp 



p dt ' 



By formula (8). 



From Zeuner. 



273 



•07201 



•07150 



323 



•04932 



•04979 



373 



•03567 



•03577 



423 



•02688 



•02685 



473 



•02090 



•02083 



(8 a) 



t_dp_21S15 

 p dt 



2-8782(7-5030- 



■log ^?). 



(9) 

 (9 a) 



t. 



p. 



t dp 

 p dt' 



From Zeuner. 



By equation 

 (9). 



By equation 



(9 a). 



212, 



4-60 



19-659 



19-69 



19-52 



323 



91-98 



15-929 



1594 



1608 



373 



760-00 



13304 



13-30 



13-34 



423 



3581-2 



11-368 



11-37 



11-36 



473 



11689-0 



9-890 



9-89 



9-85 



