are sharpened to a rough edge by means of a file. This part of the harpoon is not formed of steel, as it is frequently represented, but of common soft iron, so that when blunted it can be readily sharpened by a file, or even by scraping it with a knife. The most important part in the construction of this instrument is the shank. As this part is liable to be forcibly and suddenly extended, twisted, and bent, it requires to be made of the softest and most pliable iron. That kind which is of the most approved tenacity is made of old horse-shoe nails or _stubs_, which are formed into small rods, and two or three of these welded together, so that should a flaw happen to occur in any one of the rods, the strength of the whole might still be depended on. Some manufacturers inclose a quantity of stub-iron in a cylinder of best foreign iron, and form the shank of the harpoon out of a single rod. A test, sometimes used for trying the sufficiency of a harpoon, is to wind its shank round a bolt of inch-iron, in the form of a close spiral, then to unwind it again, and put it into a straight form. It bears this without injury in the cold state, it is considered as excellent. The breaking of a harpoon is of no less importance than the value of a whale, which is sometimes estimated at more than £1000 sterling. This consideration has induced many ingenious persons to turn their attention towards improving the construction and security of this instrument, but though various alterations have been suggested, such as forming the shank of wire, adding one or two lateral barbs, etc., etc., they have all given place to the simplicity of the ancient harpoon.