The Secret of the Silver Car / Further Adventures of Anthony Trent, Master Criminal

AUTHOR OF
THE MAN OUTSIDE; ALL THE WORLD TO NOTHING;
ANTHONY TRENT, MASTER CRIMINAL; ETC.

Stop him, the second officer yelled, he's going to jump overboard!
The man who dashed past him and through a group of passengers waving hands at friends on the deck below, was too quick for those who sought to stay him. He balanced himself for a moment on the rail and then jumped ten feet down to the pier.
The gangplanks had already been withdrawn and the great liner bound for New York was too mighty a piece of momentum to pause now. Furthermore her commander was going down the river on a favoring tide and nothing short of a signal from the port authorities would have made him put back for a passenger who had chosen such a singular moment for a leap into the dark.
An hour or so later in the smoking room the disappearance was discussed with fervor. A collar manufacturer of Troy, named Colliver, was holding his group for the reason he had been standing by the rail when the young man jumped and had even sought to restrain him.

He was too quick for me, Colliver declared. I surely thought he'd hurt himself jumping ten feet down.
What did he do after he jumped? a man demanded.
Picked himself up and looked around as if he expected to see someone. The last I saw of him was going from group to group of people asking something I couldn't hear.