"His case is up to the Federal authorities." "But when and where was the substitution made ?" asked the chief.
"On board the train to Atlanta," Britz informed him.

"Whitmore was handcuffed to the marshal when they left the Tombs.

They occupied a stateroom on one of the through parlor cars.

It is unusual for a deputy to engage a stateroom, or to permit his prisoner to engage one, but no law is violated by doing so.

All that is required of the deputy is to deliver his prisoner at the jail and obtain a receipt for him.
"The substitute followed the deputy and the prisoner into the compartment, the handcuffs were slipped from Whitmore's wrist to Timson's, and, at Philadelphia, Whitmore left the train.