While Lloyd is the comedian most identified with this peculiar comedy sub-genre in which the hero is trapped at the top of a skyscraper — on the outside — he did not invent it. Larry Semon had made several comedies in this vein as early as 1917. But Semon went off in other directions (I associate him primarily with massive TNT explosions). Lloyd periodically revisited the heights, in High and Dizzy (1920), Never Weaken (1921), Safety Last (1923), Feet First (1930) and The Sin of Harold Diddlebock (1947).
For more on silent comedy film history, including Harold Lloyd Thrill Comedies like “Look Out Below” see my book Chain of Fools: Silent Comedy and Its Legacies from Nickelodeons to Youtube