209 
possible to a sharp edge. The effect of the chamfering had, 
however, so small an effect in diminishing the rate of dis- 
charge that the determinations might have been taken from 
the cylindrical orifice without interfering with the general 
accuracy of the results. 
The mode of experimenting was similar to that already 
described. Air of an initial absolute pressure of ISolbs. was 
discharged into the atmosphere through the orifice in 
the thin plate 0, and through the orifices in A, B, C, D, E 
successively, and the times were recorded for the reduction 
of lOlbs. from each of the atmospheres of pressure, as 
shown in the following table : — - 
Table I. 
Discharge into the Atmosphere. 
Lbs. per 
square inch 
Absolute 
Pressure. 
Orifice in 
O Thin 
Plate. 
Plain 
;> Tube 
Orifice. 
Conoidal 
Cd Orifice 
Inside. 
Conoidal 
O Orifice 
Inside. 
Conoidal 
t) Orifice 
Inside. 
Double 
feJ Conoidal 
Orifice. 
Coefficient 
C for 
Orifice. 
sec. 
sec. 
sec. 
sec. 
sec. 
sec. 
135 
15-5 
14-5 
14-5 
14-5 
15-0 
15*5 
•935 
120 
17*5 
16-5 
16*5 
16-5 
17*0 
17*5 
•943 
105 
20-5 
19-0 
19’0 
19-0 
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 
30-5 
31*5 
•936 
60 
42*0 
39-5 
39-5 
39-5 
41*0 
42*0 
•940 
45 
58’0 
54*5 
54-5 
64'5 
56-5 . 
58-0 
•940 
Mean coefficient 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 difference was observable in these experiments in the 
rates of discharge through the orifices A, B, and C, notwith- 
