Page 90 - James Rodger Fleming - Fixing the sky

practical skills, combined with his use of special explosives “to keep the weather
in an unsettled condition,” could cause or at least enhance precipitation—
when conditions were favorable! Not everyone was convinced, however. 46
In 1891 Lucien I. Blake, professor of physics and electrical engineering at Kan-
sas State Agricultural College, reviewed the Dyrenforth experiments and criti-
cized the working assumption that concussion alone could make it rain. Blake
noted that the effect of “air quakes” (basically energy from sound waves) should
be immediate, yet Dyrenforth reported rain hours or days after the explosions.
Perhaps, argued Blake, the smoke and particles from the explosions had a greater
effect than the concussions. He pointed out that scientists had recently discov-
ered that moisture does not condense in dust-free air but only in the presence of
dust nuclei, or “Aitken nuclei.” Blake further observed that every hailstone had a
bit of dust in it and pointed to his own experimental seeding results with pow-
ders of carbon, silica, sulfur, and common salt that precipitated the moisture in a
condensation chamber, and on burning sulfur and gunpowder to produce heavy,
visible clouds of vapor. 47
A year later, Blake proposed a field test to produce rain in the free atmo-
sphere by raising, at intervals of about half a mile, a number of relatively inex-
pensive tethered balloons, each lifting a 30-pound smoldering ball of turpentine
mixed with sawdust, straw, or paper pulp. These would generate a considerable
smoke screen and might produce the right type of nuclei in the proper (but
not excessive) concentrations needed for rain. Although he had insufficient
funds for the field test, he claimed that his reasoning was based on sound labo-
ratory experiments and would be much cheaper than Dyrenforth’s elaborate
explosive techniques. 48
observers from afar also commented on the explosive American rainmaking
attempts. In Transactions of the Epidemiological Society of London for 1892, Sir
William Moore noted that a rainmaker in New York had exploded 200 pounds
of dynamite carried aloft by a balloon over the Croton Aqueduct and was imme-
diately rewarded with a heavy downpour. He thought it “quite possible” to pro-
duce rain, since in his understanding clouds were “masses of minute vesicles” in
an aeriform state. Their liquefaction could be caused by an explosion and the
resulting compression that forces the moisture to coalesce, become larger drops,
and fall as rain. Contrary to Powers, Ruggles, and Dyrenforth, all of whom main-
tained that concussive explosions could intervene directly in copious streams of
invisible high-altitude moisture, Moore held that the amount of rain produced
artificially would be insufficient unless clouds were already present, an unlikely
situation during droughts in tropical lands. Instead, he recommended that gov-
ernments invest in irrigation systems. 49

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