I am struck by similarities between the Keystone comedy His Musical Career and the "Ham" comedy Ham the Piano Mover, which came out less than a week apart in 1914. His Musical Career features Charlie Chaplin and Mack Swain as disportionately sized piano movers. Swain, the much larger mover, has Chaplin lift a piano on his back and carry it into a home on his own. In the closing scene, Chaplin and Swain roll down a hill with a piano and go crashing into a lake. The piano is sinking into the water as Chaplin merrily pounds the keys and launches into song.
Ham the Piano Mover had the same premise and at least one identical gag - Ham had his small partner Bud lift a heavy piano on his back and carry it into a home on his own. These similarities were likely a coincidence, but it is less a coincidence that other "Ham" comedies came to resemble Chaplin comedies. The Hobo Raid (1917), in particular, seemed to have taken its plot directly from Chaplin's The Tramp (1915). Dough and Dynamite (1914) is very much like the 1917 Ham and Bud misadventure The Deadly Doughnut. As original as Hamilton was, he occasionally was influenced by Chaplin.
Chaplin's Little Tramp preceded Hamilton's Big Tramp, but he was not the only tramp around in the days of early film comedy. The Little Tramp came along at a time that the movies were filled with funny tramps - tall tramps, fat tramps, short tramps, skinny tramps. It is possible that this trend was partly influenced by author W. H. Davies. Davies' 1910 bestselling memoirs The Autobiography of a Super-Tramp depicts tramps as charming, colorful and funny characters and describes the tramps getting involved in comical misadventures.
Davies relates a story about a tramp named Slim who is going from home to home to beg for money. He encounters a man standing outside of a shed. Davies writes, "Now, as Slim looked across, he saw into the shed, and behold there was a punching bail hanging from the ceiling, which was still moving as though this gentleman had only that moment finished practising." The man gives Slim a pair of boxing gloves and tells him that he will pay him a dollar if he spars with him for ten minutes. Slim avoids hitting the man for fear that he will knock him out and be unable to collect his dollar. The man is much less cautious and attacks Slim "like a mad bull." The man takes every opening that he gets to slam his fists into Slim, who ends up with "a bloody nose and such aching bones." This story, in terms of the characters, the humor and the violence, resembles one of the slapstick-style tramp comedies of early Hollywood.