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BRASS TACKS

Rainmakers

Last summer near Albuquerque, New Mexico some General Electric technicians set out to do something about the weather. On July 21 they vaporized ten ounces of silver iodide in a gas torch on the ground. 320 billion gallons of water, enough to fill all the reservoirs in New York, fell on the desert that afternoon. A lot of people would like to believe there was some connection.

New York City officials, for example, are betting $50,000 that the New Mexico downpour was no accident. They pay University meterologist Wallace E. Howell '36, $100 a day to try doing as well for them. On the other side of the river Jack and Irving Rosenthal, owners of Palisades Amusement Park, have offered him twice as much to go away. Although Howell has refused credit for all rainfall except a storm last Monday, the Rosenthals have had all the demonstration they need. Since he came to town, they complain, "we have not had a single day of sunny weather."

All this is glad news to thousands of parched communities from Kansas to Hawaii, who are having their first visions of rainsoaked land. Since 1946, when Dr. Vincent Schacfer of the General Electric Research Laboratories announced he had produced rain by scattering dry-ice particles in super-cooled clouds, experts and laymen alike have been enchanted by the prospect of tailor-made weather. Scores of amateurs have been up in the air ever since seeding clouds with everything from dry ice to corn flakes; one man claimed he fathered a storm with carbon dioxide from a fire extinguisher.

The United States Weather Bureau isn't convinced. Despite extravagant publicity in the press, Harry Wexler, chief of the Bureau's Special Scientific Services Division, says flatly that "it has not been demonstrated that cloud seeding is a factor in producing a significant amount of precipitation." In nine months of its own tests in Ohio the Weather Bureau got few results unless there was natural rain within 30 miles, none without natural rain within 40-60 miles. According to Wexler, the New Mexico tests were inconclusive. Rain occurred somewhere in the state whenever the researchers operated, and also when they did not.

The Bureau applauds Howell's careful approach. He is operating in certain control areas and comparing results with records of rainfall in those districts in the last 15 years. Only rain occurring downwind from the seeding plane will be considered man-made. Howell's experiments may produce the first really accurate results in the field.

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Earlier tests, conclusive or not, have called forth new theories of rain-formation. The old explanation, which the Weather Bureau still favors, worked in terms of complex systems of wind. Rainmakers claim that precipitation depends more on nature's providing enough particles on which, raindrops can form-or on man's providing artificial particles, like silver iodide nuclei. To explain how this "seeding" can result in a violent storm, they provide a detailed "chain-reaction" theory.

The technical problem is to start the whole process. Says Schaefer, "what we need to find out is how many artificial nuclei we need, when we should use them, and how often."

There are more problems than that. The legal prospects include a decision on who owns the clouds, and other questions equally without precedent. Fear of suits has led General Electric to work with the Army Signal Corps, so that a GI hand tosses the dry ice from the plane.

A bill now before Congress calls for $50 million for research on the water problem of the western states, part of which would go for research on rainmaking. Others propose that the government take over the whole business of weather control. If this goes through, readers may see the day when rainfall is determined by a House majority.

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