Many long years before you were born, when boatmen worked their profession on the canal that runs just outside The District in Maryland, a traveler was making his way to the seat of government. A very simple rustic, although dressed as somewhat of a dude, the fellow asked a boatman if he could work his passage to the southern terminus of the canal.
"That can be arranged," agreed the boatman, who considered himself a sharp operator, "but you'll have to lead the horse."
"As good as done." replied the traveler.
He took the towline, tied the end to the horse, and then led it along the bank pulling the boat in the customary manner of those days.
When they arrived many long hours later, the poor traveler sank to the turf in weariness.
"Do you call that working your passage? Why, I might just as well have walked it ..."