with which Air rushes into a Vacuum. 



543 



Table V. 



Absolute 























atmo- 







1 



2 



3 



4 



5 



6 



7 



8 





spheres. 























9 



7-5 



75 



75 



7-5 



7'5 



7-5 



75 



90 



110 



seconds. 



8 



8-5 



8-5 



8-5 



8-5 



8-5 



85 



100 



135 







7 



100 



100 



10-0 



10-0 



100 



11-0 



14-5 







n 



6 



120 



120 



120 



120 



125 



160 











5 



150 



15-0 



15-0 



15*5 



20o 













4 



200 



200 



200 



25-5 















3 



270 



27-0 



310 

















2 



43-0 



430 

















}> 



1 



97-0 



















» 



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. The ordinal 

 numbers at the head of the table indicate the atmospheres in 

 the receiver when the discharge was made, commencing with 

 vacuo ; and the time of each discharge, in seconds, is shown 

 against the pressure in the discharging and receiving cylinders 

 respectively. The times in the second and third vertical 

 columns are obtained from those in Tables I. and IV., when 

 the discharge was made into a vacuum and into the atmo- 

 sphere. On examining these results, commencing with the 

 lower pressures, it will be seen that for two atmospheres of 

 absolute pressure, the time of discharge (43 seconds) was the 

 same for a vacuum as it was w T hen made into the atmosphere, 

 as has already been demonstrated. It will also be seen that 

 a pressure of two atmospheres in the receiver acts as a vacuum 

 to four atmospheres in the discharging cylinder. This is evi- 

 dent from the equality of the time (20 seconds) when the 

 discharge was made into one atmosphere or into a vacuum. 

 The like ratio will also be observed up to three atmospheres 

 in the receiver, which act as a vacuum to the discharge of six 

 atmospheres of pressure from the small cylinder. As the 

 pressure in the receiver was increased, the diminution 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 



