78 
TRANSACTIONS OF THE TEXAS ACADEMY OF SCIENCE. 
ing point; a very insignificant transformation of energy when compared 
with the heat required to be abstracted in order to cool one cubic mile 
of the air to the temperature of saturation (page 75). Not only so, it is 
a transformation of the opposite kind to what is required; for what is 
required is cooling, not heating. The effect of the falling in of the at¬ 
mosphere was to develop an additional amount of heat, sufficient to raise 
fifteen pounds of water from the freezing to the boiling point. 
What was accomplished with this government appropriation ? The 
test of Friday was made while the atmosphere was threatening to rain; 
eight balloons, 150 shells, and 4000 pounds of rosellite were fired off; 
result, an explosion of a balloon inside a black rain cloud does not bring 
down a shower. The test of the following Wednesday was made with a 
clear sky; ten balloons, 175 shells, and 5000 pounds of rosellite were 
fired off; result, the sky remained clear. No more tests were made, but 
the rainmakers the night following, heedless of the probable deluge, 
fired off twelve balloons, 150 shells, and several thousand pounds of 
rosellite merely to get rid of them. There was no care taken to observe 
what might be looked for with some show of reason; the party expected 
a physical miracle, and they were disappointed. 
6. Chicago inventor .—At the time of the San Antonio fiasco, another 
patented plan of making rain was published, and it was said that Senator 
Farwell, who has been the main supporter at Washington of rainmaking 
appropriations, was more satisfied with it than with the concussion plan. 
It consists in freeing liquified carbonic acid in the portion of air from 
which it is desired to extract rain. The carbonic acid in vaporizing and 
expanding must be supplied with heat, which it will extract from the 
surrounding air. Here we have the proper kind of agent; but there is 
the financial question to consider. The amount of heat abstracted by 
one pound of liquid carbonic acid in volatilizing, and taking the temper¬ 
ature of 72° Fahrenheit, would change 68 pounds of water by one degree 
Centigrade of temperature. To reduce the cubic mile of air we consid¬ 
ered (page 74) to the temperature of saturation would require 129,000 tons 
of carbonic acid; to reduce it the other 11 degrees Fahrenheit would require 
an equal amount; and to absorb the latent heat would require an addi¬ 
tional 150,000 tons. If we take the price of a pound of liquefied carbonic 
acid at one dollar, the cost, supposing no waste or change of the air, of 
a rainfall of 27-100 of an inch over a square mile would be more than 
$400,000. 
7. Pitkin .—In March of this year I received from Mr. Fitkin, of 
Kansas City, a newspaper cutting in which he describes two mechanical 
methods of rain making. “ The first plan is to use two large canvas 
tubes or conduits of unequal lengths, their lower ends to be connected 
over large rotary fans run by steam power; their upper ends attached to 
