WITH WHICH AIR RUSHES INTO A VACUUM. 



161 



have seen^ by a direct comparison^ under like conditions, 

 with the amount of the discharge into a vacuum. 



Having established the fact that the atmosphere acts as 

 a vacuum to the discharge of air of all pressures above 

 two atmospheres within the range of my experiments, it 

 appeared to me that this phenomenon might only be a 

 particular case of a general law of the discharge of elastic 

 fluids, and that it would be interesting to know through 

 what range of relative pressures in two vessels the one 

 would act as a vacuum to the other. With this object air 

 was compressed into the large receiving cylinder from two 

 up to eight atmospheres absolute pressure, while air was 

 condensed into a small discharging cylinder up to nine 

 atmospheres of absolute pressure. The air was discharged 

 from the same orifice as in the former experiments, and 

 the time of discharge recorded for each atmosphere was 

 for a reduction of 5 lb. of pressure. The results obtained 

 are shown in the Table. 



Table V. 



Absolute 

 atmo- 

 spheres. 







I 



2 



3 



4 



5 



6 



7 



8 





9 

 8 



7 



7-5 

 8-5 



lO'O 



7'5 

 8-5 



lO'O 



7-5 



8-5 



lO^O 



7-5 



8-5 



lO'O 



7-5 



8'5 



lo'o 



7-5 



8-5 



ii-o 



7-5 

 lo-o 



14-5 



9-0 

 13-5 



II'O 



seco 



nds. 



6 



12-0 



I2"0 



I2'0 



I2-0 



12-5 



160 











J 



5 

 4 



15-0 

 20'0 



15-0 



15-0 

 20-0 



15-5 

 25-5 



20-5 













' 



3 

 I 



27-0 

 43-0 



97-0 



27-0 

 43-0 



31-0 

















, 



In this Table the first vertical column to the left shows 

 the number of atmospheres in the small cylinder from 

 which each discharge of 5 lb. was made into the receiver. 



SER. III. VOL. X. M 



