Okay, so technically at this musty time in history these acrobatic feats weren't called "parkour." It was just a strange man (or men – more on that in a minute) scurrying up a drainpipe, scaling a building and leaping off a bridge long before Jackie Chan's snapping ankle had entered this world.
But that doesn't make it any less impressive. The ease with which that dude ascends a tree, in particular, suggests muscles strong as oak burls and reflexes quicker than a snapping rat trap. Toss in some quality child endangerment with that alley scene, and you have a show of danger and physical prowess that would lure in crowds of suckers at Ringling Bros. and Barnum & Bailey.
And to believe one account of this leaper's identity, he did perform at a circus. The nature of this footage has been debated all around the Internet, with folks saying it's either John Ciampa, the "Human Fly" from Brooklyn who performed at the Rodeo and Thrill Circus, or Arnim Dahl, a German stuntman who's said to have fractured 100 bones. The men were contemporaries, mugging for the spotlight in the 1940s and '50s with death-defying antics like dangling from a flag 10 stories up (Dahl) and getting arrested for climbing the Astor Hotel's facade (Ciampa, who was mistaken for a suicide case).
The general consensus is that Ciampa is the guy doing more parkour-ish stuff at the beginning, and Dahl comes in later with the typical stuntman tricks of running atop speeding trains and jumping out of a high window. Traceurs and traceuses – you too, parkour dog – prepare to be wowed: