LIFE-BOAT; LIFE-PRESERVER. Many ingenious plans, more or less practicable, have been proposed for saving from drowning those who may be in peril by shipwreck or other wise. These contrivances may be classed as Life Boats, Life Buoys, and Life Dresses. Life Boats.—A life boat is a boat constructed with great strength to resist violent shocks, and at the same time possessing sufficient buoyancy to enable it to float, though loaded with men and filled with water. Such boats are maintained at most of the ports of this kingdom, always ready to put to sea when vessels are seen in danger of shipwreck, and provided with means for being conveyed to the shore, and launched as rapidly as possible. As early as the year 1785, a patent was granted to Mr. Lukin for a life boat with projecting gunwales and hollow cases or double sides under them, as well as air-tight lockers or in closures tinder the thwarts: these contrivances increased the buoyancy of the boat, and the air-tight cases under the gunwales, by their weight when raised above the surface of the sea, and their resistance when depressed be neath, greatly prevented rolling. Mr. Lukin's boat was strong and buoyant, but it was liable to be disabled by having the sides staved in. This defect was obviated in Mr. Greathead's boat, which was invented soon after ; its pre vailing feature is that the boat is lined inside and outside with cork. Mr. Greathead's boat was instrumental in saving the lives of 300 persons in five years, near Tynemouth.
In 1839 Mr. Mackintosh of New York took out a patent for a sort of temporary life boat. It consists of canvas rendered impervious to water by being saturated with a solution of caoutchouc. A square piece of this canvas is so hemmed at the edges as to leave a hollow tube or channel, which, when filled with air, may act as a buoyant cell or air-chamber. Tho opposite edges of the piece of canvas are par tially sewn together, so as to give to it the semblance of a boat, the sewn edges being cemented with caoutchouc to render them air and water tight. Mr. Adams shortly afterwards contrived a boat lined with cork in the inside, and having air-vessels under the decks or seats. Holeroft's pontoon, or safety boat, also of recent origin, has some peculiarities about it, on account of its portability. It is formed
of a skeleton frame, easily detached and folded into one-sixth of the space which it occupies as a boat. The frame is covered with layers or folds of strong canvas saturated with India rubber ; and in various parts are cases or air cells, partitioned off one from another. The portability of the boat is brought about by having the framework hinged to the keel, so that the sides close together like a portfolio. Captain Smith's peddle-box boats, for steam vessels, originated from that officer having observed that there is room, upon such pad dle boxes,for a life boat, without encumbering the ship in anyway; and builders of steamers have devised a mode of making the inverted boat a covering for the paddle box.
Every year brings forward some new pro jects relating to life boats. There was a sin gular suggestion made a year or ..wo ago by Mr. Bateman, for the construction of a wooden boat, having as many vertical cylinders as there were to be persons accommodated ; each cylinder was to he 30 inches deep by 19 in diameter. Each cylinder was to have a cover when not in use ; but when the cover was re moved, a man was to get into each cylinder, and thus seek for safety. The interstices were to be filled up with cork, and other arrangements made for lightening, strengthening, and row ing the boat.
The Duke of Northumberland has recently offered a prize for the invention of the most efficient form of life boat ; and this offer has led to the exercise of much ingenuity on the subject. One of the inventions proposed to compete for the prize is that by Messrs. Rus sell and Oswald of the Isle of Man. The boat is on the double or twin principle ; both boats being divided into ten air-tight compart ments, and completely decked over, by which arrangement they cannot be swamped. The boats are placed three feet apart; and upon them is fixed a framing, with seats and row locks for eight rowers. The bottom of each boat is a curve, rising up at both ends to a con siderable height above the water. There are arrangements for masts and sails. This boat is, we believe, to be exhibited at Hyde Park.