Fixing the Sky (28 page)

In 1891, Louis Gathman of Chicago obtained a patent to encourage and enhance rainfall by chilling the atmosphere through the release of “liquefied carbonic acid gas” shot from a projectile or released from a balloon. In Gathman's plan, the liquid carbonic acid sent into the clouds would vaporize and expand, chilling the surrounding air.
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Even though one method involved delivery of the agent by artillery burst, Gathman's idea was quite distinct from those of the concussionists. Senator Charles Farwell (R-Illinois), who had supported Robert Dyrenforth, was reportedly interested in the patent, but did not pursue the idea. Fernando Sanford, a physics professor at Stanford University, praised Gathman's theory, since he thought that cooling the air was a physically sound technique to enhance rainfall artificially. Sanford categorized Dyrenforth's recent Texas rainmaking expedition as a “national fiasco,” since the explosions of the concussionists actually heated the air and encouraged the proliferation of charlatans. Real scientists conducted carefully controlled tests and were published in the technical literature; they did not petition Congress for money on the basis of their brainstorms. Sanford wrote: “Unquestionably we have [in Gathman's proposal] the proper kind of an agent for producing rain. The only question to be considered is one of finance.”
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Unfortunately, the scale of the atmosphere worked against the idea. Sanford calculated that it would take an astronomical amount of carbonic acid, 406 million pounds of it, to cool a cubic mile of air sufficiently to generate a quarter of an inch of rainfall over 640 acres. With carbonic acid selling for $1 a pound, Sanford estimated that the cost of the rainfall per acre was a prohibitively expensive $600,000.

If Gathman had taken the next step, proposing the use of solid carbonic acid (dry ice); if Sanford had seen a triggering effect to the cloud seeding rather than a brute-force approach to chilling the entire atmosphere; and if someone had actually tried the experiment, perhaps by shelling a growing cumulus congestus cloud ... but those are a lot of “ifs.” In 1948 the
Stanford Law Review
, in an examination of the science behind the current cloud-seeding rage, briefly mentioned Gathman's patent, pointing out that minute particles of dry ice and even artificial clouds must have been formed in the rapid cooling process. They speculated that if Gathman were alive, and if his patent had not long since expired, “he might have an action for patent infringement against those who are using dry ice to cause rainfall.”
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Two more big “ifs.”

In the late nineteenth century, supercooled cloud conditions were known, and meteorologists were hinting at the possibility that ice-phase processes could initiate precipitation. In 1895 Alexander McAdie wrote that, by analogy, “a snowflake
or ice crystal falling into [a supercooled cloud] may suffice to start a sudden congelation, just as we see ice needles dart in all directions when a chilled surface of a still pond is disturbed.” Speaking of towering convective clouds—which are certainly large but not quiescent like a pond—McAdie noted, “We liken this monstrous cloud to a huge gun, loaded and quiet, but with a trigger so delicately set that a falling snowflake would discharge it.”
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He predicted that “successful rain engineers will come in time ... from the ranks of those who study and clearly understand the physical processes of cloud formation” (77). The key word here is “trigger,” which is just what the General Electric scientists were attempting to do in 1946.

Readers of the September 1930 issue of
Popular Mechanics
learned that a Dutch scientist, August Veraart, had recently “succeeded” in producing rain by throwing dry ice power (solid CO
₂
) on clouds.
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Veraart also claimed to be able to produce more sunshine by conducting his seeding in the early morning, which cleared the sky of fog, mist, and clouds for the rest of the day. From a small airplane flying above the Zuider Zee, Veraart scattered some 3,300 pounds of crushed ice particles cooled to a temperature of–78°C (–108°F) into growing cumulus clouds. Observers testified that the intervention was followed by falling streaks of rain, although there is no evidence that the rain actually reached the ground.
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In 1931 Veraart published a small popular book in Dutch, now quite rare, titled
More Sunshine in the Cloudy North, More Rain in the Tropics
. Here he presented a history of his involvement in rainmaking, an overview of his experiments and theories, and a summary of his wide, sweeping claims.
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Over the years, Veraart said, he had tried an assortment of seeding techniques involving dry ice, supercooled water-ice, and ammonium salts. He theorized that seeding particles could upset the stability or release instability in clouds, release latent heat of condensation, and perhaps influence their electrical charges to either dissolve them or condense their moisture into rain. As a kind of budding climate engineer, he speculated that the widespread application of such techniques could produce both more rain (at night) and more sunshine, while serving to purify the air and reduce the frequency and severity of storms. Veraart thought that this would make the world better by rearranging climate zones that were either too hot, too cold, too wet, or too dry.

Veraart died in 1932, before Bergeron and Findeisen published their work on cloud physics. Meteorologists have minimized Veraart's contribution, even though he was using the “right” substance, by claiming that he probably did not understand the mechanism involved in the precipitation process he triggered, he did not realize that the dry ice was effective in development of ice crystals
by cooling supercooled clouds, and his success was likely only a coincidence. Veraart's lack of an academic affiliation and his excessive enthusiasm led Dr. E. van Everdingen, head of the Royal Dutch Meteorological Service, to brand him a “non-meteorologist and charlatan.”
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Meteorologist Horace Byers wrote in 1974 that Veraart's vague concepts on changing the thermal structure of clouds, modifying temperature inversions, and creating electrical effects were not accepted by the scientific community.
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Thus, instead of Veraart, it is the scientists at GE who are remembered as the pioneers in weather control.

Schaefer was trained as a machinist and toolmaker at GE and joined Langmuir's research team in 1932, specializing in building models, devices, and prototypes. He was involved in outdoor activities, including nature study, preservation, and hiking in the Adirondack Mountains. In 1940 he became widely known for his method of replicating individual snowflakes using a thin plastic coating. On July 12, 1946, Schaefer attempted to cool off a home freezer that he was using as a cloud chamber by dropping a chunk of dry ice into it. To his surprise, he saw the cold cloud instantly transform into millions of tiny ice crystals (figure 5.1). Later measurements indicated that he had reduced the temperature of the chamber from–12 to–35°C (10 to–31°F) and had generated an ice cloud from “supercooled” water droplets. His GE laboratory notebook for the day reads: “I have just finished a set of experiments in the laboratory which I believe points out the mechanism for the production of myriads of ice crystals.”
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Schaefer later recalled

The following week, on July 17, when Langmuir returned from a trip and witnessed the effect, he scribbled in his laboratory notebook “Control of Weather” above his analysis of Schaefer's discovery.
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Schaefer recalled that Langmuir “was just ecstatic and he was very excited and said, ‘Well, we've got to get into the atmosphere and see if we can do things with natural clouds.' So I immediately began to plan ... to seed a natural cloud.”
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Speculation was rampant that summer about the possibilities of weather control. On July 31, Schaefer made some rough calculations that indicated that if a 50-pound block of dry ice, costing $2.50, could be ground up and dispersed
into a cloud from an airplane, hundreds of thousands of pounds of snow could be generated.
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Like the electrified sand researchers of the 1920s, Schaefer supposed that “precipitation” not reaching the ground would serve to dry out the clouds and dissipate them. “Thus,” he speculated, “it would seem possible with the right arrangements—barrage or captive balloons, rockets, etc., etc., to clear areas around airports, on flight paths, or possibly to precipitate snow in mountainous regions where it could be used for water storage and sport and prevent it from being deposited in cities!”
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Langmuir too was engaged in calculations of his own about the vast economic and practical consequences of seeding natural clouds with dry ice.

5.1 Vincent Schaefer reenacting his discovery on July 12, 1946, that sparked fresh weather-control experiments, as Irving Langmuir (
left
) and Bernard Vonnegut watch. Colleagues have said that he did this on innumerable occasions for anyone who would watch. (SCHAEFER PAPERS)

The public had not yet heard about cloud seeding in September 1946 when the midwestern novelist and screenwriter Homer Croy reminisced in
Harper
'
s Magazine
about the rainmakers of his youth. The article was an instant anachronism: “One day when I was just a boy, my father said, ‘Get ready and we'll go to town and see the rainmaker.' No work! Maybe a candy mouse. Maybe some ‘lickorish.' ... There were always wonderful things to be had in town. It was not long before we were in the hack and jogging along the dusty road. There, on each side of us, was the suffering, gasping, dying corn.”
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Croy recalled that in the 1890s, especially during times of drought, many people sought the services of rainmakers. He and his family gathered that day with other citizens at the railroad depot where the Rock Island Railroad had sent its rainmaker to work his magic from a specially equipped boxcar. There was

But by the end of the afternoon, only a little cloud, “about as big as a horseblanket,” appeared and suddenly disappeared in the otherwise cloudless sky. Croy and his family returned home that evening disappointed but not disillusioned. As they prepared for bed, they heard, on the tin roof of the shed, a hopeful pitter-pat that soon became a downpour—the soaking rains had started. The next morning “everything in all the world was all right. The drought was broken. And we knew why it had been broken.... And we were thankful to God for the wonderful man who had come among us” (217).

In his essay, Croy relegated these events to the gullibility of a bygone era, concluding, “There is now not a farmer in all the corn belt who believes in rainmakers. ... It hardly seems possible today that I once went to town to see a rainmaker save our crops, but I believed in it then and so did most people” (220). The timing could not have been more ironic. Croy's article was published in
Harper
'
s
just
after
Schaefer's discovery of dry ice seeding and just
before
General Electric announced it to the public, initiating a new wave of faith and hope in weather control—and a resurgence of commercial rainmakers.

On November 13, 1946, the General Electric News Bureau announced that laboratory cold box experiments had succeeded in making snowflakes and that scientists would soon conduct an outdoor experiment to see if they could exercise “some human control over snow clouds.”
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The
New York Times
headline read, “Scientist Creates Real Snowflakes.”
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November 13 was also the day that Schaefer conducted an airborne test by dropping 6 pounds of dry ice pellets into a cold cloud over Mount Greylock in the nearby Berkshires, creating ice crystals and streaks of snow along a 3-mile path. This marked the beginning of a new era of cloud seeding.
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Here is Schaefer's account of the test flight: