Image Credit: The Atmosphere, published by Prentice Hall (2001)
Miss C's post The Tesla's Tower of Power - about Nikola Tesla's never-completed project of building a tower to control the weather (among other things) got me looking for other weather modification past projects.
Here's a strange one from Austria, circa 1899:
Weather modification has been around since the beginning of recorded history, when people used prayer, dances, wizardry, and black magic. It was not until near the beginning of the 20th century that more drastic measures were taken toward weather modification. The first major device was tested in Austria for two years and was named "hail cannon". These 300 feet tall cannons were muzzle-loaded and shaped like a cone cylinder. They used it to fire mortars into the clouds believing that the smoke particles would prevent hail by acting as condensation nuclei.
After completing a two-year test, no hail was observed in Austria, while the surrounding provinces had severe hail damage. Believing that this test proved that the cannons were successful, other areas in Europe began using them for the protection of their cash crops. This resulted in a "cannon fever" in Europe which made Italy deploy over 2000 cannons by 1899. The fever was soon lost when the cannons proved ineffective. Although this attempt and many others failed, inventors also developed successful weather modification inventions during the nineteenth century. Some of these are smudge pots, sprinklers, and wind machines used to fight frost
http://snr.unl.edu/metr351-03/brockman/introduction.html - via BLDGBLOG (a neat blog about architecture, btw)