184 MR. H. WILDE ON THE EFFLUX OF AIR AS 



Table I. — Discharge into the Atmosphere. 



Lbs. per 



Orifice 



Plain 



Conoiclal 



Conoidal 



Conoidal 



Double 



Coeffi- 



square 



inch 



absolute 



in thin 



tube 



orifice 



orifice 



orifice 



conoidal 



cient for 



plate. 



orifice. 



inside. 



inside. 



inside. 



orifice. 



orifice. 



pressure. 







A 



B 







D 



E 









sec. 



sec. 



sec. 



sec. 



see. 



sec. 





'35 



i5'5 



14-5 



i4"5 



14-5 



15-0 



155 



•935 



1 20 



17-5 



i6-5 



i6-5 



i6-5 



17-0 



17-5 



•943 



105 



20*5 



19-0 



i9"o 



i9'o 



20-0 



20-5 



•927 



90 



25'0 



23-5 



23-5 



23"5 



24-5 



25'0 



•940 



75 



31-5 



29-5 



29-5 



29-5 



3o"5 



3i"5 



•936 



60 



42*0 



39-5 



39"5 



39"5 



4i'o 



42-0 



•940 



45 



58'o 



54-5 



54-5 



54-5 



56-5 



58-0 



•940 



Mean coefiicient for orifice in thin plate "937. 



An examination of this Table will show that the form of 

 the orifice has very little influence on the rate of discharge, 

 of elastic fluids compared with what it has on those which 

 are inelastic. 



No diff'erence was observable in these experiments in 

 the rates of discharge through the orifices K, B^ and C, 

 notwithstanding that A was a plain cylinder, and B and C 

 were coned to a depth of half their thickness and formed 

 tubes from three to six diameters in length. Moreover, 

 although the results shown in the Tables were obtained 

 with the coned sides of the orifices inside the vessel ; yet, 

 when the sides were reversed, the rate of discharge through 

 A, B, and C was only diminished by one-thirtieth part, 

 and there was no difi'erence in the rate of discharge 

 through D whether the coned side of the orifice was inside 

 or outside the vessel. 



Taking A, B, and C as the orifices producing the maxi- 

 mum rate of discharge, we have "935 as the value of the 

 coefficient of discharge from an orifice in a thin plate for 

 the highest pressure of 135 lbs. This value, as will be 

 seen, is the same for all the pressures in the Table within 



