The Admiral, one of the best practical sailors of his day, thus explained it:-- "In the first place," said Sir Samuel, "you must observe, youngsters, that this device of the natives is neither more nor less than a floating windlass, where the buoyant power of the timber serves the purpose of a support to the axis.

The men fixed by the slew-ropes to the cylinder, represent the handspikes or bars by which the windlass is turned round, and the hawser takes the place of the cable.

But," continued he, "there appears to be no reason why the cylinder should be made equally large along its whole length; and were I to repeat this experiment, I would make the middle part, round which the hawser was to be passed, of a single topmast, while I would swell out the ends of my cylinder or raft to three or four feet in diameter.

In this way a great increase of power would evidently be gained by those who worked the slew-ropes.

In the next place," said the Admiral, "it is clear that either the buoy-rope, or another hawser also fastened to the anchor, as a 'preventer,' ought to be carried round the middle part of the cylinder, but in the opposite direction to that of the weighing hawser.