"But then, how could they get the ships in?" asked Rollo.
"Ah, yes," said Mr. George; "I forgot about that. It was necessary to have passage ways
leading in from the river, with walls and gates, and with drawbridges over them."
"What do they want the drawbridges for?" asked Rollo.
"So that the people that are at work there can go across," said Mr. George. "The people who live along the bank of the river, between the basin and the bank, would of course have occasion to pass to and fro, and they must have a bridge across the outlet of the docks. But then, this bridge, if it were permanent, would be in the way of the ships in passing in and out; and so it must be made a drawbridge.
"Then, besides," continued Mr. George, "they need drawbridges across the passage ways within the docks; for the workmen have to go back and forth continually, in prosecuting the work of loading and unloading the ships and in warping them in and out."
"Yes," said Rollo. "There is a vessel that they are warping in now."
Rollo understood very well what was meant by warping; but as many of the readers of this book may live far from the sea, or may, from other causes, have not had opportunities to learn much about the manœuvring of ships, I ought to explain that this term denotes a mode of moving
vessels for short distances by means of a line, either rope or cable, which is fastened at one end outside the ship, and then is drawn in at the other by the sailors on board. When this operation is performed in a dock, for example, one end of the line is carried forward some little distance towards the direction in which they wish the vessel to go, and is made fast there to a pile, or ring, or post, or some other suitable fixture on the quay, or on board another vessel. The other end of the line, which has remained all the time on board the ship, is now attached to the capstan or the windlass, and the line is drawn in. By this means the vessel is pulled ahead.
Vessels are sometimes warped for short distances up a river, when the wind and current are both against her, so that she cannot proceed in any other way. In this case the outer end of the line is often fastened to a tree.