Like gigantic ear horns in reverse, these Victorian-era cannons project sound explosions deep into the sky, hoping that the power of the shockwave will prevent the formation of hail. It’s supposed to protect delicate crops from damage. Wikipedia expresses doubts.
Like lepidoptery and ballooning, a modified version of the hail cannon survives into the modern era. In fact, you can buy them here.
Watch this video to hear what they sound like (although the cannons themselves don’t appear):
I think if hail cannons worked, there would be better evidence of it — and insurance companies would refuse to pay out for hail damage to your car if you didn’t use the hail cannon that was included as a mandatory piece of protection equipment in the small print of your policy.
Since I don’t live anywhere near one, a part of me is thrilled that they exist. I wonder if they work on crows?
I’ve been following the hail cannon discussion for several years on my blog,
Evidence Soup. A classic example of the triumph of hope over evidence.
–Tracy Allison Altman, Evidence Soup