140 Mr. T. Hopkins on the Formation 



often above 52°, steam cannot be said to form at any time here 

 much more than 1 per cent, of the atmosphere. The gases 

 then being considered as 99, and steam as 1, the liberated 

 caloric would attach itself to a much greater extent to the 

 gases than to the remaining steam. The elasticity of the 

 gases would be thereby increased; they would spring up, and 

 carry the remainder of the steam with them to a sufficient 

 height to cause fresh condensation to take place, and thus the 

 process might be continued ; not only is steam a very small 

 portion of the whole atmosphere, but it cools according to a 

 different law to that which regulates the cooling of the gases, 

 and the difference in the laws by which the steam and the 

 gases cool, causes the latter to cool the former. In ascending 

 in the atmosphere, it is found that, when undisturbed by re- 

 cent condensation, the temperature is reduced about 1° for 

 every hundred yards of elevation. But the steam and the gases 

 separately cool nearly according to the following table, taking 

 whole numbers in a regular series as a sufficient approxima- 

 tion to the truth for our present purpose : — 



At a height of about 1700 feet steam cools, say 1°, while the gases cool 5°. 



3400 ... 2° ... 10°. 



5000 ... 3° ... 15°. 



10,000 ... 6° ... 30°. 



Here we see that in an ascending column of steam and 

 gases intermixed, while the former would by their ascension 

 cool by expansion only one degree, the latter would cool five 

 degrees ; the gases, therefore, in their ascent would act the 

 part of coolers to the steam. Being. intimately intermixed the 

 colder body would abstract heat from the warmer, and practi- 

 cally the gases when they rise must cool the steam that is in- 

 termixed with them. Then, as the steam is condensed more 

 caloric is given out, and the gases again warmed and ex- 

 panded ; and thus these different elastic fluids, condensable 

 and non-condensable, act and react upon each other, and give 

 results different from those which would be found if they ex- 

 isted in the atmospheric space separately from each other. 

 A portion of the atmosphere, nearly saturated with steam, 

 being raised by a force acting from below to a height of 

 1700 feet, the steam within it would be cooled, according to 

 its own law of cooling, 1°; but the gases, by their different 

 law of cooling, would be cooled 5°; and as these fluids would 

 be intimately intermixed, the lower temperature of the gases 

 must, to a greater or less extent, be communicated to the 

 steam, and a partial condensation of the latter must follow. 

 This condensation we have seen would give out caloric, which, 

 by raising the temperature of the remaining steam, would cer- 



