28 
Table IV, 
Discharge into the Atmosphere. 
Barometer 29*64, Thermometer 58° F. 
Effective 
pressure in lbs. 
per 
square inch. 
Time of 
discharge 
in 
seconds. 
Apparent 
velocity 
per' second. 
Velocity 
coefficient 
•62. 
120 
7*5 
843 
1360 
115 
7*75 
852 
1374 
no 
8-0 
862 
1390 
105 
8-5 
852 
1374 
100 
9*0 
843 
1360 
95 
9*5 
842 
1360 
90 
10-0 
843 
1360 
85 
10*5 
851 
1372 
80 
11-0 
863 
1392 
75 
12-0 
844 
1362 
70 
13*0 
836 
1348 
65 
14*0 
833 
1344 
60 
15-0 
843 
1360 
55 
16*5 
837 
1350 
50 
18-0 
843 
1360 
45 
20-0 
843 
1360 
40 
22-0 
863 
1392 
35 
24*5 
886 
1429 
30 
27*0 
935 
1509 
25 
31*0 
980 
1581 
20 
36-0 
1053 
1699 
15 
43-0 
1178 
1900 
10 
58-0 
1311 
2114 
In this table it will be observed that the times of each 
discharge from 120 lbs. to 15 lbs, effective pressure into the 
atmosphere are identical with the times of discharge from 
135 lbs. to 30 lbs. absolute pressure into a vacuum. Hence 
we are able to formulate and prove the general proposition 
that the atmosphere acts as a vacuum, and offers no resis- 
tance, to the discharge of air of all pressures above two 
absolute atmospheres. 
Although the times of discharge for each reduction of 
5 lbs. of pressure, as we have seen, are the same as those 
