The barbed head or mouth is eight inches long, and six broad; the shank, with its socket, two feet and a-half long.

The shank is not quite half an inch in diameter; and as this part is liable to be forcibly extended, twisted, and bent, it requires to be made of the toughest and most pliable iron.
A piece of small, but stout line, called, I think, the foreganger, is spliced securely to the shank of the harpoon.

To the end of this line is attached any small rope that lies handiest on the forecastle, probably the top-gallant clew-line, or the jib down-haul.

The rope, before being made fast to the foreganger, is rove through a block attached to some part of the bowsprit, or to the foremost swifter of the fore-rigging; a gang of hands are always ready to take hold of the end, and run the fish right out of the water when pierced by the iron.
The harpooner has nothing to attend to but the mere act of striking his object; and there are few exploits in which the dexterity of one person is more conspicuous over that of another than in delivering the harpoon.

I have heard Captain Scoresby say, that, when a whale is struck, it is an object of importance to drive the weapon socket-deep into the blubber, or outer rind, of the floating monster; but in the case of the porpoise the true point of skill appears to lie in the aim alone: for the mere weight of the instrument, with its loaded staff, is sufficient to lodge the barbs in the body of the fish, and in many cases to carry it right through to the other side.
The strength of the porpoise must be very great, for I have seen him twist a whale harpoon several times round, and eventually tear himself off by main force.