Boy (Harold Lloyd), trying to impress girl, gets chased by her father and the police right into an ongoing marathon.
Although many of Harold Lloyd's films around 1920 were directed by Hal Roach, this one has the distinction of coming from a different man: Australian-born American film director Alfred J. Goulding, who also worked with Laurel and Hardy.
There are plenty of gags in this one, including the use of a midget, a small dog, and an impressive mirror joke. Whether the mirror was originated here or not I do not know, but it has been repeated countless times since, most often in cartoons. (Lloyd's comedy could probably be favorably compared to a cartoon.) One website says the definitive version of the joke is in 1933 Marx Brothers film "Duck Soup", who got it from vaudeville... but who first put it on screen?