SCIENTIFIC AND USEFUL.

New Zealand Graphic, Volume XIV, Issue I, 5 January 1895, Page 8

SCIENTIFIC AND USEFUL.

SAFE AND NOVEL. A safety boiler of a somewhat novel character has been devised by M. Chateu', a French engineer. The boiler consists of a nest of horizontal tubes placed over the furnace. Into this neat water is injected in the form of spray, under which conditions it is instantaneously evaporated and super-heated, no • solid ’ water, if such a term is allowable, being ever admitted to the tubes. It is stated that the tubes do not burn out, and that the evaporative power of the boiler is especially remarkable. THE MENOTHKRM. A simple apparatus, called the * menotherm,’ has been devised for applying steady and continuous heat to any part of the surface of the body where it is required 'for medical purposes. It consists of a flat rubber pad connected to a small copper cylinder or heater by two rubber tubes, the whole being filled with water and hermetically sealed. Io nee, the cylinder is placed in a can of water over a lamp. The water in the cylinder is thus heated and caused to circulate through the pad, the temperature being regulated by the height of the lamp flame. SIGNALLING. The signalling apparatus invented by Captain Prince Louis of Battenberg and Captain Percy Scott consists of a collapsible drum, attached to the masthead, the code used being the Morse alphabet. One advantage of the new invention lies, it is said, in the fact that protection is afforded to the signalman, so that it will be possible to transmit signals in action. Some doubts have, we learn, been expressed as to whether the drum will stand the pressure to which it will necessarily be exposed when steaming head to wind. A * BARRICADE ' LI FEBUOY. If a sai'or falls overboard in rough weather it may sometimes be more than half an hour before a boat can reach him, and the sea may be infes ed with sharks. To meet this danger a special * B trricade ’ lifebuoy has been invented, for which the following features are claimed. It is not unwieldy on deck, the mechanism is simple both in construction and nse, the apparatus is .reversible, so that when it is thrown into the water there is no need to turn it over, and once the wearer is enveloped in it he is said to be effectually protected against the attacks of sharks. LARGE OPTICAL TRAIN. A rock salt prism and set of lenses are being made by Mr Brashear for the Smithsonian Institution, and, when completed, will probably be the largest optical train yet cohstructed of this material. The 60 degieee prism is stated to be seven inches high, and the width of each face five inches. The lenses are seven inches in diameter. The prism is not perfectly free from flaws, but it is considered that the loss of light from this cause will hardly be more than 5 per cent., and the lenses are even clearer than the prism. All three pieces were cut from a block of lock salt which formed part of Russian mining exhibit at the late World’s Fair. COBWEBS. Cobwebs are still valueless as a raw material for manu* factoring purposes, and, like many another article, remarks the Drapers Record, await the ingeuity of man to turn them to better account in the service of man. No thoughtful observer of the wonderful elastic web of the common garden spider, for example, can resist the temptation to speculate on the possibilities of the spider and its web. Indeed, considering the rate of progress in arts and sciences, we onght not to be quite so far, contends our contemporary, from the day when the cob webs in the cellar will be carefully collected and converted into silk dresses for the ball-room. NEW SAFETY’ LETTER BOX A new safety letter box, invented by Mr Dutton, has a couple of serrated strips of thin metal fixed above and below the slit, inside, projecting an inch or more into the box, and bent a little towards each other so as to practically narrow the letter slit inwardly, but pliant enough to give sufficiently if a large packet has to be introduced. The object of the patent is to prevent the unlawful abstraction of letters by means of anything thrust in to get hold of them, as the letters, in the attempt to draw them out, would be caught under or behind the serrated metal pro j setions. It is a simple arrangement, but seems to adequately answer the purpose for which it is devised. A FRIEND IN ELECTRICITY. The brunette who desires to be a blonde has a friend in electricity. An American contemporary reports that a process has been invented whereby the hair is first dampened with a bleaching compound, then passed through a metallic brush, connected with a current, the fair subject resting the back of her neck on a metal plate. A slight decomposition of the salt held in solution takes place, the bleaching agent is liberated, and, it is stated, the colouring matter in the hair lightened. The same ingenious inventor, by f >rcing an inflammation with a so called Faradie current, is also prepared to make * coral lips' for anybody who wants them. TO DARKEN GREY HAIR Lockyer’s Sulphur Hair Restorer, quickest, safest, best; restores the natural colour. Lockyer’s, the real English Hair R-istorer. Lsrge bottles, 1.61, everywhere —( YDVr )