76 
TRANSACTIONS OF THE TEXAS ACADEMY OF SCIENCE. 
Mr. Dyrenforth leaves out one essential point in the calculation. Over 
what area was the 9,000,000 tons of coal to be burned daily? Anyhow the 
result given by the ‘calculation ought to have staggered him in the belief 
that he could accomplish a comparable result by means of a few insignifi¬ 
cant explosions. It is evident that to heat the air produces, in the first 
place at least, the opposite effect to what is desired; and in any case the 
subsequent cooling by expansion must first abstract all the heat supplied 
from the coal before it can take out the further heat required to reduce 
the air to the temperature of condensation. If moist air could be made 
to ascend by a process which does not heat it, such process would be more 
effective and less expensive. 
3. Powers .—In 1870, Mr. Edward Powers, of Delavan, Wisconsin, 
published a collection of statistics in a volume entitled, “War and the 
Weather.” By means of these random statistics he establishes the re¬ 
markable truism, that battles are followed by rain; but he nowhere proves 
that battles are necessarily accompanied by rain, or that a day of battle 
is followed more quickly by rain than is a day of no battle. His inves¬ 
tigation is a glaring example of the fallacy of post hoc ergo propter hoc , 
further vitiated with the fallacy of neglecting to consider rains which do 
not follow battles. Without having tested his hypothesis on a small 
scale, he petitioned Congress to make an appropriation to test it on a 
large scale. Two hundred seige guns which lie idle at the United States 
Arsenal at Rock Island, Illinois, were to be taken to a suitable locality 
in the West, and one hundred rounds to be fired from them in each of 
two operations, the estimated cost of the two operations being $161,000. 
This shows anyhow that Mr. Powers had some slight idea of the expens¬ 
iveness of rain making. lie does not explain how the sound and heat 
due to the firing of the cannon are to take the heat out of the air in order 
that the vapor may condense. He does not show how the condensation 
is to start, but he makes the gratuitous assumption that the latent heat 
developed by condensation will help on the process instead of retard¬ 
ing it. 
Compare Aitken and Powers. The former devises crucial experiments 
and reasons from the results; the latter deals in so-called facts and cranky 
arguments. The one puts a distinct question to nature; the other deals 
in one-sided and random statistics. The one believes that truth may be 
found by experimenting on the air in his cellar at his own expense; the 
other lectures and lobbies to get the National Congress to test his crank 
theory on a large scale at a cost to the country of $160,000. In the one 
we have a philosopher; in the other a crank. 
4. Buggies .—In 1880, Daniel Ruggles, of Fredericksburg, Virginia, 
patented a process for producing rain. The invention, as described by 
Mr. Ruggles, consists of “a balloon carrying torpedoes and cartridges 
