Man has always had a need for speed: legs to outrun bears, horses to overtake enemies, cars to cross continents, meth to ... oh, different thing. But we've been constructing ways to enjoy speed, too, since at least the 1400s. That's when we find one of the early incarnations of man's more aimless speed freakery — the roller coaster. Patrons on Russia's "ice slides" would climb a 70-foot timber tower, sit on a sled, and then whooooosh down a 600-foot ice ramp to the base of a second tower. There they'd repeat the thrill, slipping down a parallel slide back to the start. Popular among the gentry, these rides were a winter pursuit until speed-demon Catherine the Great put the rollers on the coaster, adding wheels and grooved tracks to make a summer version at her palace in 1784. Then the French took the coaster baton and ran with it: In 1817, Belleville Mountain in Paris became the first slide to lock cars onto tracks by their wheel axles. And the city's Aerial Walks, which had two curving tracks that met at the base of the ride, introduced a system for pulling the cars back up for "rerides." The French also developed the first successful loop in 1846 — the 13-footer was tested using sandbags, monkeys, and one intrepid worker, whose reaction was recorded in the Journal du Havre. It will ring familiar to any thrill-seeker: He "experienced such a delicious feeling that he wanted to try again."