Manufacturing the Weather

James Rodger Fleming

During a dry spell in the late summer of 1891, but conveniently at the (commonly known) onset of the annual rainy season in the Texas Panhandle, Dyrenforth and his ersatz army engaged in “a perfect imitation of battle”—a war on drought. Without taking any careful or systematic measurements—they did not have a rain gauge and their meteorologist left early—the team took credit for every shower of rain that fell, near or far, before or after the barrages. Local citizens were entertained and duly impressed, but the press had a field day. F. W. Clarke’s humorous poem “Tale of the Rain Machine,” published in Life in 1891, was inspired by the Dyrenforth experiments. In the poem the hapless farmer Jeremy Jonathan Joseph Jones seeks to break a drought using “cannon, and mortars, and lots of shells, and dynamite by the ton, with a gas balloon and a chime of bells, and various other mystic spells to overcloud the sun.” His third shot into a cloudless sky “brought a heavydew”; his fourth, tornadoes, “thunder, rain, and hail.” Jeremy drowned in the ensuing flood, and his farm became a lake. All efforts to stop the deluge were in vain, “Until the Bureau at Washington stirred, and stopped the storm with a single word, by just predicting—Rain!”

Fog dissipation for aviation safety took center stage in the second quarter of the 20th century. Experiments on electrified sand dispersed from aircraft, chemical sprays on airfields, and the FIDO (Fog Investigation and Dispersal Operation) fog burners of World War II all attracted high-level military support. “Fliers Bring Rain with Electric Sand,” a New York Times headline announced in 1923. The story itself, however, was underwhelming. Between 1921 and 1923 field trials conducted in Dayton, Ohio, at McCook Field seemed to show that electrified sand could dissipate clouds and might someday both dispel fog and generate artificial rain. The demonstrations were the brainchild of the controversial Cornell University chemist Wilder Bancroft and his entrepreneurial sidekick L. Francis Warren, a self-styled and self-taught independent inventor and dreamer who frequently misstated his credentials as “Dr. Warren of Harvard University.”

Although the hope of clearing fogs, making rain, and driving mists from cities, harbors, and flying fields was great, the hype was even greater. Electrical precipitators had long been used for removing smoke, dust, and fumes from industrial gases, but these operated in enclosed spaces, not in the free atmosphere. Theory seemed to indicate that sprinkling electrically charged sand above fog or clouds would lead to the coalescence of the cloud droplets. In practice it was fraught with problems and met with only limited success. The May 1923 issue of Popular Science Monthly described the Warren-Bancroft demonstrations as follows: “Think of it! Rain when you want it. Sunshine when you want it. Los Angeles weather in Pittsburgh and April showers for the arid deserts of the West. Man in control of the heavens—to turn them on or shut them off as he wishes.” None of this ever happened. Bancroft nearly went broke supporting Warren’s commercial brainstorms. By 1925 the military, which provided aircraft facilities, quietly withdrew its support for the project.

Increasing Power, Growing Concerns

A decade later Henry G. Houghton of the Massachusetts Institute of Technology tried spraying solutions of calcium chloride and other chemical drying agents from an array of pipes installed over an airfield. With fog continually rolling in from the ocean, Houghton realized the impracticability of this approach, but his work provided support for later operational aircraft-deicing treatments. During World War II the British developed FIDO—a brute force approach, not unrelated to Espy’s giant fires, that burned thousands of gallons of gasoline to drive off the fog and create a lighted, heated runway that gave Allied fliers the edge over their German counterparts. A crash program initiated during Britain’s darkest hours, FIDO was credited with saving thousands of airmen’s lives but was much too expensive for commercial use. The main technique for dealing with fog, developed after the war, was not weather or cloud modification but the widespread use of instrumented landing techniques.