ALEXANDER MACFARLANE-RAINMAKING. 
75 
a cubic mile of that air to the dew point would require the abstraction of 
as much heat as would raise 88,000 tons of water from the freezing point 
to the boiling point. To cool it down another 11 degrees would re¬ 
quire as much more heat to be abstracted. The amount of water set free 
would be 20,000 tons, which spread over a square mile would give about 
1.4 pounds per square foot, or 27-100 of an inch of rainfall. The amount 
of latent heat set free by the condensation of that amount of water would 
raise 100,000 tons of water from the freezing point to the boiling point; 
and it would be necessary to absorb this heat in order that the rainmak¬ 
ing might go on. I have supposed the cubic mile of air to be kept con¬ 
stant; if the air operated on is constantly changing, the task becomes one 
of infinitely greater difficulty. 
Let us consider now how the different rainmakers propose to accom¬ 
plish this remarkable feat. , 
1. Melbourne .—In Kansas there is a Professor Melbourne, who has 
taken contracts to make rain. For the slight sum of $500 he contracted 
to cause a rainfall of half an inch over a circle of country 100 miles in 
diameter. He is called the Australian rain maker. I recollect that some 
twelve years ago there was an account hi the newspapers of attempts at 
rainmaking in Australia. The country was suffering from prolonged 
drouth, and I believe that the firing of cannon was actually tried. Prob¬ 
ably it was then that Melbourne discovered his method, or borrowed it 
from the Bushmen. He came to Temple, Texas, hired a shanty on the 
outskirts of the town, shut himself and an assistant in, and all observers 
out. All that could be observed from the outside was the issue of some 
colored gas through a small pipe in the roof of the shanty. The pro¬ 
ceedings of this impostor were gravely discussed by intelligent people; 
so great is the ignorance of physical nature. 
2. Espy. —Mr. Dyrenforth in his article in the North American Re¬ 
view, October, 1891, refers to a plan proposed by Professor Espy, which 
was considered by the government of New South Wales: 
“In 1837, Professor Espy, at that time a well known scientist, pro¬ 
posed a method of compelling nature to loose the moisture which she 
holds suspended aloft. His plan was to kindle great fires which would 
produce a powerful upward current of hot air, and this rising to a great 
height where, owing to diminished pressure, it would expand, by the ex¬ 
pansion would be cooled, thereby condensing and eventually precipitat¬ 
ing its moisture. The Australian government proposed in 1884 to make 
a test of Espy’s theory; but when Mr. H. C. Russell, the government 
astronomer of New South Wales, demonstrated that it would require 
9,000,000 tons of coal burned daily to increase by 66 per cent the rain¬ 
fall of Sydney, where the average humidity is 73, the project was forth¬ 
with abandoned.’ ’ 
