Buster runs to a pier and jumps on a departing boat. Unfortunately, it goes back to the dock and the cops get on. Keaton hides on the paddle wheel. When the boat leaves he must run on the wheel (like a hamster on an exercise wheel).
A passing wagon leaves a trial of dirt. Because the bottom dropped out of his cart, the dirt just lands on the street after Buster sweeps it up and deposits it. Luckily, when he moves his cart it's over an open manhole, and the dirt disappears - only to reappear all over a workman who comes out, wallops Keaton, and goes back down.
Keaton goes up a fire escape and into a building with two cops on his tail. He goes out the window and rides the counterweight to the ground. The cops get on the escape, but Keaton attaches the weight to a truck so the ladder won't go down. The truck drives off and the ladder dangles from the building by a cable.
The first cop comes looking for Keaton, not noticing the Keatonesque store dummy. Both cops leave, and Keaton gets down. He puts on the pants with the wallet. The Keaton-chasing cop comes back and the owner asks for payment for the pants. Keaton finds the wallet and pays. The cop, not recognizing him, shakes his hand, but Keaton leaves.
Keaton runs down a street, pursued by hundreds of cops. He grabs hold of the back of a streetcar and his feet fly up. He hauls himself in and salutes the cops, but the car arrives at the end of the line, turns around, and catches back up to the cops. Keaton, distracted by his newspaper, doesn't notice.
When Buster Keaton was filming Sherlock Jr. he broke his neck on the train track scene. He didn't find out about his broken neck until he had his routine examination which was years later.