Few things would be more convenient than the ability to control the weather, but the technologies we've developed toward that end haven't exactly made life easier. Hail cannons, which predate the invention of gunpowder, experienced a brief revival in the late 19th century when residents of Styria (in modern-day Austria) devised a special gas-based mortar supposedly capable of preventing hail. By the year 1900, more than 10,000 hail guns had cropped up across Western Europe. Given their popularity, it's a shame that the cannons proved useless. Scientists commissioned by the Austrian and Italian governments dismissed the weather guns after finding that they failed to "agitate" the air or change the composition of clouds. Even if the mortar could affect one oncoming storm, it was highly unlikely that they could prevent future hailstorms altogether.
Read the full story in "Jostling the Clouds to Change the Weather"