Before we close this article we must briefly notice Mr. Clint's ballasted masts for small sailing vessels, the object of which invention is to enable the boat constantly to retain an upright position, the mast alone yielding to the force of the wind. Fig.1 is a section of the vessel, and Fig. 2 a plan of the same. a represents the hull of the vessel ; b an oblong caisson of a semicircular section, suspended at each end upon pivots in the deck beams, at the point c. The mast is stepped in a trunk in this caisson, and secured by shrouds brought down to the sides of the caisson, and by a fore-stay proceeding to the stern of the vessel, and by a back-stay to the stern. The ballast is placed evenly in the bottom of the caisson. Among the advantages claimed by Mr. Clint for this construction are, first, perfect safety, as he considers it impossible a vessel can ever capsize. Secondly, the vessel being always upright, is constantly on what are termed bee lines, and is always in trim, whereby she will sail faster and go better to wind ward ; and lastly, that the ballast being suspended in air, is of more effect than ballast placed in the bottom, which latter being identified with the vessel in the water, loses as much of its weight as is equivalent to its bulk of water, whilst the sus pended ballast retaining its whole weight, a smaller quantity will be required to steady the mast, and the vessel itself requiring none, 7 a great degree of buoyancy is obtained. Mr. Clint con structed a small vessel on this principle, and made a regular series of experi ments during the summer of 1825, in presence of a number of scientific per sons, and officers and sea men of the navy, some of whom accompanied him to Gravesend, when it blew fresh ; and from the great satisfaction given by its performances, the Society of Arts voted Mr. Clint their large medal, or twenty guineas. This invention is only intended for such vessels as are not employed in carrying cargoes, of which class are revenue cutters, pleasure yachts, &c.; nor is it intended for vessels above seventy tons, which may have the box decked in.
BOAT (Lira). A boat invented by Mr. Henry Greathead, of South Shields, for the purpose of preserving the lives of shipwrecked persons; and so well has it answer4 and indeed, exceeded, every expectation in the most tremendous broken sea, that since its invention not fewer than 200 lives have been saved at the entrance of the Tyne alone, which otherwise must have been lost; and in no instance has it failed. The principle of this boat appears to have been suggested by the following simple facts : Take a prolate spheroid and divide it into quarters, in the line of its longer axis ; each quarter is elliptical, and nearly resembles the half of a wooden bowl, having a curvature with projecting ends; this being thrown into the sea or broken water, cannot he upset, or lie with the bottom upwards. The length of the boat is 30 feet, the breadth 10 feet, the depth from the top of the gunwale to the lower part of the keel amidships, 3 feet 3 mches ; from the gunwale to the platform within 2 feet 4 inches ; from the top of the sterns (both ends being alike) to the horizontal line of the bottom of the keel 5 feet 9 inches. The sides from the under part of the gunwale along the whole length of the regular shear extending 21 feet flinches, are cased with layers of cork to the depth of 1 foot 4 inches downwards, and the thickness at the top 4 inches, projecting a little without the gunwale ; the cork on the out side is secured with thin plate or slips of copper, and the boat is fastened with copper nails. The thwarts or seats are five in number, double banked, that is, two rowers sit upon each thwart, so that the boat can be rowed by ten oars. The side oars are short, with iron tholes and rope grommets, so that the rower can pull either way. The boat is steered by an oar at each end, and the steering oar is one-third longer than the aide oars. The platform along the bottom is horizontal, the length of the midships, and elevated at the ends for the con venience of the steersman. The internal part of the boat next the sides, from the under part of the thwarts down to the platform, is cased with cork, the whole quantity of which affixed to the life-boat is nearly 7 cwt. The parti cular construction of this boat will be best understood by referring to the engraving, Fig. 1 representing a cross section of the boat, and Fig. 2 a longi tudinal elevation. F F the outside coatings of cork ; G G the inside cork fittings; H 11 the outside planks of the boat ; I I the stems ; K the keel ; N N timber heads ; P the thwarts, or rowers' seats ; It stanchion to support the thwart ; S section of a gang-board, which crosses the thwarts and forms the passage from one end of the boat to the other. T the platform for the
rowers' feet ; U U the two bilge pieces, nearly level with the keel ; W W the gunwales ; X X ring bolts for the headfast, one at each end; Y platform for the steersman ; E E E the sheer or curve of the boat; L L the aprons, to strengthen the stems ; M M the sheets, or places for passengers ; 0 0 0 the tholes on which the oars are hung by grommets. After the value of the invention was attested by the presentation of a gold medallion to Mr. Greathead, by the Society of Arts, as also one by the Royal Humane Society, and various gratuities in money, parliament in 1802 unanimously voted him 1,2001. The Committee of Under writers at Lloyd's Coffee House, having voted Mr. Greathead 100 guineas, appropriated 20001. of their funds for the purpose of encouraging the building of life-boats on different parts of the coasts of the kingdom. Great numbers of these boats have since been constructed for all parts of our coasts, as well as for those of foreign nations. But as it most frequently happens that vessels are wrecked on coasts where there are no life-boats, or that from the darkness of the night or the strength of the wind and sea a life boat may not be able to reach the vessel in time to afford succour, it is highly desirable that all vessels should carry with them the means of safety for their crews; and accordingly numerous plans have been suggested of converting the ordinary boats of a ship into life-boats to meet these emergencies. Of these plans we select that of Captain Henry Gordon as amongst the most simple and efficacious, whilst it in nowise interferes with the ordinary services for which the boats may be required. It consists in attaching to the exterior of the boat a species of buoy, of a trian gular form, which, whilst it adds greatly to the buoyancy of the boat, saves it from concussions, offers little obstruction to its progress, and can be attached or removed as occasion may require, with great facility and dispatch. Fig. 1 (page 195) shows the buoy ; Fig. 2 an end view of the same ; and Fig.3 represents it fitted to a boat. The buoy is composed of fine Spanish cork, and consists of eight rows, each row being a foot longer than that immediately below it. Each row is constructed of pieces of cork 1 foot long, 6 inches wide, and about It inch thick, laid three thicknesses together, and then placed end to end till of the required length, (which in the drawing is represented at nine feet for the upuer streak,) and then formed into one streak by lengths of split bamboo, on all four sides, and well sewed together by strong cord covered with shoe maker's wax. The different streaks are fastened together by four ropes, which are seized together between each streak ; when used, the ends are drawn under the keel till the lower streak touches it, and then brought up over the side and fastened to the thwarts ; the other triangle is in like manner drawn up under the boat's bottom on the opposite side and fastened. Two buoys to the scale of that shown in the engraving contain 14i cubic feet of water; and if attached to a boat 28 feet long, and capable of containing twenty-four men, would leave a buoyancy of 718 lbs. for their support. Large boats, such as those capable of containing f 100 men, instead of a single large triangle on each side, should have three of 9 feet length each, by which means the same triangles might be made to serve boats of different sizes, by which the expenses of outfit would be materially reduced, and triangles of the above dimensions would also be more manageable, easier put on or taken off, and more easily stowed away than large ones. Thus the launch, rowing twenty-four oars, with seventy-five men on board, might be fitted in the following manner : the barge's triangle fixed amidships, the cutter's on the bow, and the jolly boat's on the quarter; the launch weld then be rendered completely buoyant without any additional expense. The contrivance combines several advantages ; it is extremely simple, and offers the best security under similar circumstances; it is so reason able in its cost as to admit of every merchant vessel being supplied with it; and not being a fixture, it can be at any time removed, so as to be no additional weight when a boat is being hoisted in or out. It is particularly advantageous for the preventive service, to approach vessels and visit them when no other boat can ; for a blow that would stave a boat, would not penetrate the triangle owing to its elasticity. At sea, also, it might take up a drowning man in a gale of wind, when no other boat could live.