Page 157 - James Rodger Fleming - Fixing the sky

A full demonstration for the military was held at dawn on June 24, 1942, at
Vrooman’s Nose, a 600-foot cliff that provided a panoramic view of an agricul-
tural region in upstate New York known as the Schoharie Valley. Notables in
attendance included Vannevar Bush and Alan Waterman of the oSRD, Vladimir
K. Zworykin of RCA Research Labs (prominent in chapter 7), and top military
officers. on cue, at sunrise, with drainage winds flowing down the valley, a tiny
puff of smoke from a single Langmuir–Schaefer generator rose in the distance and
quickly spread to fill the valley floor. The device worked by forcing 100 gallons
o
o
of lubricating oil at a temperature of about 450 C (842 F) at supersonic speeds
through a hot manifold. As the oil vapor hit the cold air, it formed a dense white
cloud of tiny particles. Within minutes, the generator had belched out a persistent,
thick smoke screen 1 mile wide, 10 miles long, and 1,000 feet deep, totally obscur-
ing the valley. The army had its smoke screen, GE its contract, and Langmuir and
Schaefer had taken their first steps in the new field of cloud physics. Since they had
made an artificial cloud successfully, why not modify an existing one? 7
In 1943, again under military patronage, Langmuir’s research team shifted its
attention to studies of electrical effects such as precipitation static, which inter-
fered with radio communications during snowstorms. The Mount Washington
observatory in New Hampshire provided ideal conditions for their experiments
and, serendipitously, led them into the study of the behavior of clouds contain-
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o
ing water droplets as cold as –40 C (–40 F) (“quite a bit below freezing”). Such
conditions represented the typical environment for clouds in the free atmo-
sphere and provided insights into the nature of ice nuclei, ice deposition, and
other aspects of cloud physics. “In the process,” according to an interview with
Schaefer, “Langmuir and I became very much interested in the whole business
of supercooled clouds, and whether you could modify them.” The military roots
of weather control research should not be surprising, given the earlier history of
army aviators using electrified sand and chemicals for cloud busting and the con-
temporaneous effort to clear fog in England using the FIDo system.
Langmuir and his team read the latest articles by meteorologists Alfred Wegener,
Tor Bergeron, Walter Findeisen, and other European researchers on the initiation of
ice-phase precipitation. Schaefer again took the lead, seeding supercooled clouds of
water droplets with “dozens of different materials”: talc, carbon, graphite, volcanic
dust, various smokes, and quartz crystals—following an idea attributed to Findeisen
that the crystals might provide suitable cloud condensation nuclei (this “didn’t work
at all”). Yet Schaefer persisted in his “cut and try” methods, emulating Thomas Edi-
8
son’s search for a suitable lamp filament. Rather than theory, it was Schaefer’s use
of dry ice to cool his cloud chamber in the summer of 1947 that opened up a new
9
chapter in the history of weather control. others had tried this before.

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