NOTES ON SCIENCE, MECHANICAL INVENTIONS, ETC.

New Zealand Herald, Volume XXV, Issue 9124, 4 August 1888, Page 4 (Supplement)

NOTES ON SCIENCE, MECHANICAL INVENTIONS, ETC.

A NEW LIFEBOAT.

Some interesting experiments were made ' lately at St. George's Dock, Liverpool, with • a new lifeboat, the invention of Messrs. i Gray and Hughes, and built by Mr. R. R. Gray, at his works at the Queen's Dock. The boat is 16 feet in length, with a beam , of 5 feet 6 inches, and 2 feet 6 inches in . depth. She is built of galvanised steel , sheets, and is in twenty water-tight compartments. When not in use, she can be transformed into a deck seat. When in this form, directly she is lowered, or in any way touches the water, she folds together, and is kept in position by a clip at- each end of the boat., which is at once screwed up. The boat will hold from twenty-five to thirty passengers, and has life-lines outside her bulwarks, which will assist as many more in keeping afloat. She will carry over four tons dead weight. The watertight compartments are so built that they can be used for storing food, etc. The lifeboat can also be fitted with two masts, and has eight lifebuoys, which can be instantly detached and thrown overboard. Experiments were made to illustrate the modus opcramii of putting her into the water in this case by means of a crane, which lowered the boat into the water. Immediately on touching the water, the boat was transformed from a dock seat into a lifeboat fully equipped for a voyage. Several people then got in, and were rowed about the dock, after which she was hoisted up and resumed her position as a deck seat. It is stated that the boat can be put into the water in any position, but will always right herself. NEW LIKE-SAVING DEVICE. A United States navy officer has invented a life-saving device for the dreaded emergency of " man overboard" which promises to be of value. A raft-buoy of sufficient size to support a man is attached to the vessel by a long and strong but light wirerope. The buoy is stocked with a small supply of provisions, and is furnished with a potassium compound which upon contact with the water ignites and burns brilliantly for twenty minutes. If the drowning man, aided by the flame, succeeds in reaching the raft, he can be drawn to the vessel without the necessity of lowering boats. Should the rope break and his own vessel lose track of him, he has, with the provisions, a chance of sustaining life until picked up by others. BALLOONING WITHOUT LOSS OF GAS. There is much mysterious talk in military circles (says a Paris correspondent) of a balloon, the invention of a M. de Villars, in which the problem of aerial navigation is said to be solved, at least to a degree never yet reached M. de Villars' aim has been to direct his balloon by taking advantage of the several air currents which are to be met with at various heights. To do this, it is necessary to ascend and descend frequently in the course of a voyage. But with balloons of ordinary construction this is impossible, by reason of the loss of gas and ballast which such manoeuvres occasion. M. de Villars has no ballast to throw away, and he is able to retain the whole of his gas. Here lies the invention, which is kept profoundly secret. The inventor has, it is said, sold his secret to the French Government, to be used by it alone. Leaving out this part of the device, I may describe the balloon as consisting of a double envelope of calico, covered with a special varnish to afford greater security to the aeronaut, and to render leakage of gas impossible. The additional weight thus occasioned is compensated by making the net of a new sort of fibre, which, while being twice as strong as hemp, is only half the weight. The car, which is attached in the usual manner, is described as cylindrico-conical, and is furnished with an electric motor driven by a dry battery. This motor will actuate a screw propeller, to be used only when it becomes necessary to temporarily direct the course of the balloon. ANOTHER GREAT BRIDGE. It is proposed to bridge the Hudson River between New York and .Jersey city. The scheme is not new, but it has only now been put into practical shape by Mr. Gu.=tav Lindenthal, an American engineer of some note. The proposed structure is to be i a suspension bridge of three spans, under which the largest ships may pass. The bridge is for the New York Terminal Railway, over which all the roads centring in New York that carry passengers across the river in ferries may in future pass. In the city a central depot will be constructed. The nature of the river is such that, in order not to interfere with navigation, it will have to be crossed in one span, which must be 2850 feet, or about half a mile in length. The materials used will have to possess extraordinary strength to resist the strain and pressure, and it is calculated that the cables will each have to be four feet in diameter. Two towers will be built, each 500 feet high down to the wharf lines, and the monster cables will be swung fastened in masonry 300 feet long. Between the towers and the masonry two shorter spans, both ! together about the length of the middle one, will be suspended. The bridge will be wide enough to hold six tracks, strong enough to carry six trains at the same time, and rather over a mile long.—lron. MISCELLANEOUS ITEMS. The affection known as writer's cramps is not confined to the users of the pen, but appears in telegraphers and others who make continual use of one set of muscles. These cramps were long regarded as incurable. During several years past, however, Wolff has been applying gymnastics combined with massage to the muscles affected, and has succeeded in curing more than half of the many cases treated. His process is neither difficult nor tedious, being simply regular movements of the fingers or other parts, with rubbing or gentle striking of the muscles, continued not more than an hour a day for several weeks. Dr. Worms, of the Paris Academy of Medicine, has ascertained that bees, ants, and wasps, show a marked dislike to the new saccharine. To the human palate there is no difference in the taste between it and sugar. It has been shown, however, that its use disturbs digestion. According to recent experiments, strych nine undoubtedly neutralises the intoxicating and narcotic effects of alcohol. It enables large quantities of alcohol to be taken for a considerable stretch of time without causing the usual organic lesions which follow the use of alcohol alone. Therapeutically, strychnine should be used in all forms of alcoholism ; it may be regarded as a powerful prophylactic against alcoholism. Electricity is to be enlisted in the investigation of the purity of water. The voltameter fails to show any current passing through chemically pure water. As saline or acid contamination increases, the conductivity of the mediums grows greater. It is predicted that the borings through the Straits of Dover will reveal the existence of extensive coal beds. Some European towns forbid the occupation of newly built houses until four months after completion, as there are nearly five thousand gallons of water used in the mortar and building of 50,000 bricks, which should first dry out. A German c jmpany has patented a process for producing surface colourations upon articles made of copper, zinc, or brass Upon the first-named metal it is possible to develop all the colours of the rainbow, and upon zinc the coating is formed of such thickness as to permit of chasing the surface. The most important application of this invention seems to be in the imitation of antique bronze, the results in this direction being very satisfactory, both in the matter of durability and resemblance. Platinum can be made to adhere to gold by soldering in the following- manner :—A small quantity of fine or eighteen carat gold should besweated into the surface of the platinum at nearly a white heat, so that the gold shall soak into the face of the platinum. Ordinary solder will then firmly adhere to the face obtained in this manner. Hard solder acts by partially fusing and combining with the surfaces to be joined, and platinum alone will not fuse or combine with any solder at a temperature anything like the fusing point of ordinary gold solder. In generating steam, experiments under various boilers show 1000 feet of gas to be equal in heating power to from 80 to 133 pounds of different kinds of coal. One pound of coal equals in value 7£ feet of natural gas. The latter explodes violently when mixed with 9 to 14 parts of air. When burned with pure oxygen, the flame temperature of the natural gas is estimated at 7100 degrees centigrade. When burned with just enough air to secure perfect combustion, the temperatures are estimated at '2333 degrees centigrade for natural gas and 1700 degrees for Siemens.