380 SCIENCE IN SHORT CHAPTERS. 



ometcr tube as a unit, that pressure is doubled, trebled, 

 etc., up to twenty times in the first column. The second 

 column states the temperature at which water boils when 

 under the different pressures thus indicated. The third 

 column, which is the subject for special study just now, 

 shows how much we must rise the temperature of the water 

 in order to make it boil as we go on adding atmospheres of 

 pressure; or, in other words, the increase of temperature 

 due to each increase of one atmosphere of pressure. The 

 figures are founded on the experiments of Regnault. 



Pressure in Temperature, F. Rise of Temperature 



Atmospheres for each additional 



1 212 



2 249-5 37-5 



3 273-3 .... 23-8 



4 291-2 17-9 



5 306-0 14-8 



6 318-2 12-2 



7 329-6 11-4 



8 339-5 9-9 



9 348-4 8-9 



10 356-6 8-2 



11 364-2 7-6 



12 371-1 6-9 



13 377-8 6-7 



14 384-0 6-2 



15 390-0 ... 6-0 



16 395-4 5-4 



17 400-8 5-4 



18 405-9 51 



19 410-8 4-9 



20 415-4 4-6 



It may be seen from tJie above that, with the exception 

 of one irregularity, there is a continual diminution of the 

 additional temperature which is required to overcome an 

 additional atmosphere of pressure, and if this goes on as 

 the pressure and temperatures advance, we may ultimately 

 reach a curious condition a temperature at which addi- 

 tional pressure will demand no additional temperature to 

 maintain the gaseous state; or, in other words, a tempera- 

 ture may be reached at which no amount of pressure can 

 condense steam into water, or at which the gaseous and 

 liquid states merge or become indifferent. 



