“If the ferry-boat were headed square across the river, the current would not move her any way but down the river,” added Dory.
“There was a big wire rope stretched across the
river, which did not let her go down the stream,” replied John Brattle. “Then the boat was turned to an angle half-way between the direction of the current and the wire rope.”
“Precisely as our sails are set at an angle with the course of the boat. In this position the friction of the water against the boat forces it across the river.”
“But you have no wire rope.”
“We have a centre-board instead.” Dory pointed out the centre-board of the Goldwing, and showed how it worked. “This boat would slide off sideways if it were not for that.”
“But we have to go a great deal farther when beating,” said Ned Bellows.
“Of course we do,” replied Dory. “Sometimes we have to go two miles to make one when the wind is dead ahead.”
“Captain Gildrock said it was twenty miles from Burlington to Beech Hill. Must we go forty miles to get there?” asked Ben Ludlow.
“Not at all: the wind isn’t dead ahead. Here we are, just north of Willsborough Point. I am coming about now. Look out for your heads when the boom goes over.”