SCIENCE AND INDUSTRY.

Star (Christchurch), Issue 4739, 2 September 1893, Page 1

SCIENCE AND INDUSTRY.

Layaoid is a cement for iron and atone that is now being introduced by a Vienna firm. The Austrian authorities apeak of the compound in the highest terms. It consists of sulphur, iron, silicic acid, and alumina, and it is used in a molten condition. Its applications in iron and stone work are stated to be numerous. It serves also as an electric insulator. It melts at 125deg C, and cools quickly.

Another attempt is being made in, England to utilize the power absorbed in the application of the brakes to tram cars, so as to render aid in restarting the car. A spring is charged, wnich can be released, and will start the car without the aid of the horses. A forward and not a recoil movement is at once given to the wheels, but its 1 action can be reveraedin case of need, snob, as overrunning points at junctions. A trial of several months haß been given to the apparatus with satisfactory results up to the present.

One of the latest useß of aluminum is for cooking utensils. An expert of the metallurgical laboratory of Lehigh University says, after two yeara of actual experience, that in point of lightness, cleanliness, durability, and all-round adaptability, vessels of aluminum are the perfection of ' cooking utensils. He instances two boilers ' which have been in daily use for cooking ! all sorts of food, for preserving, stewing fruit?, and the like for two years, and are to-day a 8 bright as new, and have not lost a fraction of their weight.

The man who invents a method of joining the leather of machinery belts bo that it will be as strong at the point of union as elsewhere has an enormouß fortune' in waiting for him. A machine belt threepixteenths of an inch thick will sustain 675 pounds of weight per inch of width. At the splices, after the belt haß been fastened with rivets, this is reduced to 380 pounds ; lacing reduces it still further to 200 pounds, while a safe working tension is only about fifty pounds per inch. If the belts could be made solid and as strong at the joints as elsewhere the working tension might be largely increased.

Some curious experiments have recently been carried out at Brest, having for their object the creation artificially of volumes of smoke, under the cover of which a torpedo boat can approach a hostile ship without being itself visible. The idea seems to be impracticable ; but it has been conaidored worthy of protection by a patent, and its inventor M. Oriolle, of Nantes, is confident of ultimate succesa albeit he speaks of " the consequences which may follow upon the discovery of a sure means of producing smoke or fog of. sufficient stability and permanence." It is singular that one eet of warlike inventors should be busy upon the problem of doing away"with smoke, while another is looking for a sure means of producing it in large quantities.

Naval science seems to be going ahead about as fast as the romancers can get on in their imaginings. The French, for instance, are doing with submarine boats almost more than their fiction writers have managed to get into their books. A new submarine boat has juat been launched and sent sculling about under water, which contains a crew of twelve men. Hitherto the number of men accommodated in these under-water craft has seldom if ever gone above five. This boat is in the shape of a fish, and it carries a torpedo at its head. How it discharges the torpedo forward without coming to grief itself is not explained, but this may be a state secret. Everything on board ia worked by electricity.

The Raub locomotive is attracting Attention in the railroad world. The di» tinguiahing feature is that the pistons are placed vertically instead of horizontally* They . are three in number, instead of two, and are located between two boilers which are wholly independent of each other The piston rods are attached to a crank Bhaft, each attachment making an angle of sixty degrees with the other two bo ad to avoid the dead centre. The driving rods are attached to the crank shaft and are lifted up and pushed down instead of being driven by force exerted horizontally aa in ordinary locomotives. The inventor claims extraordinary power, and the two boilers give him Bteam capacity to reach one hundred miles an hour with a good* sized train without any trouble. The cab is between the two boilers,and the ends of the locomotive are right and left duplicate! of each other, so the locomotive looki equally well and works equally well running in either direction. The pre-' liminary teats are said to have resulted very satisfactorily.

Chemists and othera .interested in the discovery and nee of new explosives are now busy studying the component parts and character of an aoid recently discovered by a chemist, and to which he has given the name of hydrazoic acid. This, it is claimed, is destined to make a new era in the hißtory of explosives. The new acid has been christened hydra* zoic aoid from its composition, which it three parts of nitrogen and one part of hydrogen. It aeema strange that in alii

the years that chemi&try has been studied this aoid has escaped discovery till now. It is described as reseinblinij water, fuming strongly in contact with the air and cauaing painful wounds when applied to the skin. The acid does not seem t-> be itself explosive, but the salts it forms with most \ ■of the metals are described as being extremely so. Ifc was discovered accidentally, it Beems, during the course of an obEcare organic investigation, and the strangeness of its properties led t:> an investigation, • and the discovery of the txaot nature ot its characteristics. Fen specimens exist jn-tbis country (America), and the acid hasnot been studed to any gre'.\t extent. .A, scheme for electric-photography appears in a Paris photographic journal. The fundamental idea of the method ia plain enough: A copy of the negative is taken upon a gelatine film, and the film, aa-iB known, offers an uneven surface j its plane areas correspond to the whites of ' th"c photo, while the, darter parts of the latter appear more or leso in" relief. The film is •■ accordingly fixed upon a : oy Under,.. which is made to rotate by ' electrioity .at s speed of twenty rairolutions. per minute. A thin needle tonohea ita surface in such a way a 9 to describe a helical line on the cylinder, and t> toneh in turn every spot of the surface of the photo. Each time the needle comes upon a relief it is lifted ; and as it forms rarbof an electric circuit, the current is weakened by this movement. The current is transmitted in the use a' wj along a .-wire to the next station. Tkire another cylinder, covered with parsifine wax, is .made to rotate at exictiy the same sp3ed, and another needle, moved by the current, precisely imitate? the movements of the first. It thus engraves on wax an exact reproduction of the gelatine film, from : which a typographic copy is taken in the 'ordinary way. The teletype, or eleetrioal typewriter, baa been designed to ineeb the requirements of a rapid and reliable printing telegraph instrument, which haß long been needed, This instrument is manipulated very much in the same way as a typewriter. The transmitter as well as the receiver mates a copy of the message, and the liability of mistakes is thus largely decreased. The instruments work in unison, and it is impossible ta Bend a message from one machine unless the corrsEponding machine at the end of the. distant Jiae is properly receiving. The record is plainly printed on fch'9 strip- of moving paper in. front of the operator. The fact that the message is printed at the other end of the line without any personal attention, makes the arrangement exceedingly valuable. As will be readily seen, it will be of special benefit to business houses whei-9 rapid and accurate communication is desired with their factories and distant place 3; for communication between small towns, where the business doe 3 not warrant the services of a skilled Morse operator ; for use on iailroads, where the presence of the station agent is not actually required at tha instrument while a mesEage is bsing recsived j he can then attend to eueh other duties as requ're his presence-, elsewhere, and on his return will find the message printed out. The instrument is likely to De in demand also for police and municipal service, where £he intercommunication between the several stations and offices of the city government .should be as prompt and easy a* possible. Tb.9 same instrument can send' and receive.