Spoiler alert: group of fun-loving French folks build an animal-or-human-powered merry-go-round that spins fast enough to fling all takers into the lake (YouTube, embedded below). Actually, that’s basically it. The surprise is ruined, but you probably want to check out the video anyway, because it looks like a ton of fun.
Granted, you may not have a well-stocked metal shop or a team of oxen up by the lake wherever you live, but there are certainly details in the video that will survive in translation. Basically, the team took the axle off of a junked car, attached it to a pole in the middle of the lake, made a large wooden drive wheel, and wrapped an infinite length of rope around it.
[Charles] from [Mad Cow] wrote us that there was about a 10:1 ratio between the drive wheel and the arms of the people-flinger. So if the cattle were pulling at 3 km/h, the human angular velocity was a brisk 30 km/h! Then it’s just a matter of convincing a team of cows, or a team of soccer players (?), to put their backs into it.
The [Mad Cow] crew seems to have more than their fair share of engineering dangerous fun up at their summer hideaway: check out their human crossbow that we featured a few years back.
