198 Prof. 0. Reynolds on the Flow of Gases. 



where t is the time. Or, since tdp = b lbs., 

 •835 



K= 



we have 



Pit 









f the value of 



Pit 



in the first six experi 







Yn 





p. K. 





Velocity 



Vj* 







at orifice. 



P 



135 ... *825 



. . . 



1022 



... 650 



130 ... -826 



.. . 



?? 



... ,, 



125 ... -835 



... 



» 



... J, 



120 ... -820 



. . . 



?j 



... ,, 



115 ... -810 



. . . 



a 



... ,, 



110 ... -790 



... 



?j 



?? 



(22) 



For the first three of these experiments K is nearly con- 

 stant, showing that the conduction of heat could have but 

 slight if any effect, but the effect is decidedly apparent in the 

 next three. 



Proceeding now to the other extreme, and assuming that 

 the temperature, after undergoing some diminution, remains 

 constant, we have 



dp_Q, 



or, integrating, 



[ °ge 





Q 



logp^logp^yloge.; 



from which, taking the last three experiments in Table 2, 



p- 



K. 



Yn. 





4 . 



. -95 . 



. 1022 . 



Pi 



.. 650 



3 . 



.. -98 ., 



• ?? • 



• • j) 



2 . 



.. -89 . 



?> 



» 



In these it appears that the values of K are approximating 

 to the value "825 ; but the great differences show that the 

 temperature effect is far from having become steady, and 

 are quite sufficient to explain the discrepancies in the actual 

 values of K. There is thus no reason to doubt but that 

 •825 is about the real value of the coefficient of contraction 

 for the orifice, and that the experimental results are quanti- 

 tatively in accordance with the theory. 



