LIFE-BOAT. A boat originally made at Shields, in 1789, by Mr. Greathead, for saving the crews of shipwrecked vessels. The following are the general principles : The boat is wide and shallow ; the head and stern are alike, for pulling in either direction, and raised, to meet the waves ; itpulls double-banked, the oars being fir, for lightness, and fitted with thole pins and grummets, and is steered with an oar. The boat is cased round inside, on the upper part, with cork, in order to se cure her buoyancy with as many persons as she can carry, even though full of wa ter; the cork likewise assists in main taining, or, if overset, in recovering, the position of stable equilibrium. The boat is painted white, to be conspicuous in emerging from the hollow of the sea. It is a curious fact that the smugglers paint their boats white for the contrary reason, because dark-colored objects alone are discernible in dark nights.
If a spheroid be divided into quarters, each quarter is elliptical, and resembles the half of a wooden bowl, having a cur ratUre with projecting ends. Such a ves sel thrown into the sea cannot be upset, or lie with the bottom upwards, owing to the ends. The length is 30 feet, the breadth 10 feet ; the depth from the top of the gunwale to the lower part of the keel in midships, 3 feet 3 inches ; from the gunwale to the platform (within), 2 feet 4 inches ; from the top of the stems (both ends being similar) to the horizon tal line of the bottom of the keel, 5 feet 9 inches. The keel is a plank of 3 inches thick, of a proportionate breadth in mid ships, narrowing gradually towards the ends, to the breadth of the stems at the bottom, and forming a great convexity downwards. The stems are segments of a circle, with a considerable rake. The bottom section, to the floor-heads, is a curve fore and aft, with the sweep of the keel. The floor- timber has a small rise, curving from the keel to the floor-heads. A bilge-plank is wrought-in on each side, next the floor-heads, with a double-rab bet groove, of a similar thickness with the keel ; and, on the outside of this, are fixed two bilge-trees, corresponding near ly with the level of the keel. The ends
of the bottom section form that fine kind of entrance observable in the lower part of the bow of the fishing-boat, called a cobble, much used in the north. From this part to the top of the stem it is more elliptical, forming a considerable projec tion. The sides, from the floor-heads to the top of the gunwale, Haunch off' on each side in proportion to above half the breadth of the floor. The breadth is con tinued far forwards towards the ends, leaving a sufficient length of straight side at the top. The sheer is regular along the straight side, and more elevated to wards the ends. Thegunwale fixed to the outside is three inches thick.
The sides, from the under part of the gunwale, along the whole length of the regular sheer, extending 21 feet 6 inches, are cased with layers of cork, to the depth of 16 inches downwards; and the thickness of this casing of cork being 4 inches, it projects at the top a little with out the gunwale. The cork, on the out side, is secured with thin plates or slips of copper, and the boat is fastened with copper nails. The thwarts, or seats, are five in number, double-banked; conse quently, the boat may be rowed with 10 oars. The thwarts are firmly stanchion ed. The side-oars are short, with iron tholes and rope grummets, so that the rower can pull either way. The boat is steered with an oar at each end; and the steering-oar is one-third longer than the rowing-oar. The platform placed at the bottom, within the boat, is horizontal, the length of the midships, and elevated at the ends, for the convenience of the steersman, to give him a greater power with the oar. The internal part of the boat next the sides, from the under part of the thwarts down to the platform, is eased with cork ; the whole quantity of which, affixed to the life-boat, is nearly seven cwt. The cork contributes much to the buoyancy of the boat, and is a good defence in going alongside a vessel, and is of use in keeping the boat in an erect position in the sea, or rather for giving a very lively and quick disposition to reco ver from any sudden cant or lurch, which she may receive from the stroke of a heavy wave.