33 
of resistance of the recipient atmospheres becomes still 
more marked, till for the highest pressures, we have the 
remarkable phenomenon of six atmospheres acting as a 
vacuum to the discharge of nine atmospheres of pressure. 
That this peculiar relation of the discharging and receiving 
atmospheres has not reached its full limit, will be obvious 
from a comparison of the numbers in the table, from which 
it would appear that for pressures exceeding those used in 
these experiments, the resistance of the recipient atmos- 
pheres would be still further diminished correlatively with 
an increase in the amount of discharge. 
With the object of giving more completeness to this 
research, experiments were made to ascertain through what 
range of relative densities the air in two vessels would act 
as a vacuum to the other for pressures below that of the 
atmosphere. The results are shown in Table VI., which are 
arranged in the same manner as those in Table V. The 
times in the second vertical column are taken from those 
shown in Table II. when the discharge was made into a 
vacuum for each lb. of pressure, and the other times in the 
Table are those obtained for successive discharges into air 
of different densities below the atmosphere; — the large 
cylinder being again used as a receiver. 
Table VI. 
Lbs. per 
square 
inch. 
0 
1 
2 
4 
6 
8 
10 
12 
14 j 
15 
16-0 
16-0 
16-0 
16-0 
16-0 
I6-5 
18-0 
21-5 
35-5 
seconds 
14 
17-5 
17-5 
17-5 
17-5 
17-5 
18-5 
20-5 
26-5 
12 
21-0 
21-0 
21-0 
21-0 
21-0 
22-5 
30-0 
JJ 
10 
25*6 
25-5 
25-5 
25-5 
26-5 
33-5 
)) 
8 
32-5 
32*5 
32-5 
32-5 
38-0 
M 
6 
45-0 
45’0 
45-0 
47-5 
>> 
4 
70-0 
70-0 
72-0 
JJ 
2 
180-0 
190-0 
35 
