Unlike today's film stars, the actors of the silent era were often expected to risk life and limb by performing their own stunts.
The renowned magician Harry Houdini swam the rapids of Niagara Falls in "The Man From Beyond", and leapt from the wing of one airborne aircraft onto another in "The Grim Game". Weirdly enough, when a six-month-old Joseph Keaton survived a fall down a flight of stairs unhurt, Houdini nicknamed him 'Buster'.
Buster Keaton survived many a fall - and a broken neck after the contents of a water tower emptied themselves onto his head in "Sherlock Jr". In the same film he rides a motorcycle no-handed, and sitting the wrong way around. Keaton allowed the front of a house to fall on him for "Steamboat Bill Jr", and those are real boulders rolling after him in "Seven Chances".
It wasn't just the men either. In DW Griffith's "Way Down East" (1920), it really is the great Lilian Gish on the slab of ice floating down river who gets rescued moments before drifting over a waterfall.
Not surprisingly, injuries were common in the trade. Harold Lloyd lost two of his fingers when a cherry bomb exploded in his hands. Others paid a higher price, like the motor-racing stuntman and actor Wallace Reid. He was so popular that despite being involved in a train crash, his studio forced him to complete "Valley of the Giants" on massive doses of morphine. They were only too happy to continue supplying the drug which eventually contributed to his death.