Rain, according to this take on meteorology, could also be impeded by noise. In the Europe of the Middle Ages, Barnett writes, bell-ringers would run to church steeples—not to warn villagers of bad weather, but in hopes of weakening the storm. ("Of course," she notes, "clutching the end of a wet rope hung from the tallest point in the village in the days before lightning rods was not the wisest way to ride out a thunderstorm. Prior to the Enlightenment, it was not uncommon for church-bell ringers to be killed by lightning.")
All those ideas—the connection between commotion and precipitation—carried on into the 19th century. When the Erie Canal was completed in 1825, thousands of revelers congregated along its path to celebrate the new waterway. The parties were loud; they involved, among other things, a series of 32-pound cannons that had been placed along the canal's wandering route, at every 10 miles or so. They involved what one spectator called "deafening fireworks." They involved artillery companies demonstrating their wares. They involved church bells and marching bands and all manner of human revelry.
The celebrations took place on a crystal-skied Wednesday; they were cut short, on Thursday, by dampening storms that had entered the area. The connection, it seemed to many, was clear: They had made a racket, and the rains had come. The people had summoned the storm.
The United States' first official meteorologist, James Pollard Espy, had a different different take on the theory of storm development. Espy had helped to create a national weather-forecasting network, the first of its kind, via a series of connected by telegraph lines. He was also famous lecturer about weather—people referred to him fondly as the "Storm King"—and had developed a convective theory of rainfall: the idea that storms are driven by warm, humid air that rises in a column. It wasn't the noise of battle and celebration that had summoned the rain, Espy believed; it was the warmth that the ruckus had generated.
It followed, he thought, that if heat brought rain … all you had to do, if you wanted to generate a rain cloud, was to generate some heat of your own. If you wanted to make it rain, you had to start a fire.
Espy, widely respected for his work with the telegraph networks, proposed a bold—some said overly bold—plan to Congress. He wanted the federal government to set aside land that would function as, essentially, a massive timber farm. The farm, he thought, should stretch in a long line, running north to south, from the Great Lakes to the Gulf of Mexico, all along the United States' Western frontier. When farmers needed rain, he thought, the forests could simply be strategically burned—bringing with them, convective heat being what it is, land-quenching moisture.
Espy repeatedly asked Congress to let him start forest fires along a 600-mile stretch of land—the better to test his theory.