104 Atmosphere. 



same treatise, viz. that the air here 

 about the surface of the earth, when the 

 pressure is taken from it, dilates into 

 10,000, and even at last into 13,679 times 

 its space ; and this altogether by its own 

 expansive force, without the help of fire. 

 In fact, it appears, that the air we breathe 

 is compressed by its own \veight into at 

 least the 13,679th part of the space it 

 would possess in vacua. But, if the same 

 air be condensed by art, the space it 

 would take up when dilated, to that it 

 possesses when condensed, will be, accor- 

 ding to the same author's experiments, 

 as 550.0OO to 1. 



Our direct experiments, however, not 

 reaching to any great heights into the re- 

 gions of the atmosphere, and not know- 

 ing how far air may be expanded, we are 

 incapable of determining to what height 

 the atmosphere is actually extended. 



