SCIENTIFIC.

Otago Witness, Issue 1645, 2 June 1883, Page 28

SCIENTIFIC.

— Dr Beckhert, of Spandau, has patented in Germany an india-iubber oil which is intended to serve as a protective against rust. According to the description published in the German technical Press, the rough oils obtained in the dry distillation of brown coal, peat, or other bituminous substances are subjected to further distillation. Thinly rolled india-rubber cut into small strips is saturated with a four- fold quantity of this oil, and is let stand for 80 days. This mass, thus composed, is subjected to the action of vulcan oil, or a similar liquid, until a homogeneous, clear substance, is formed. If this substance is applied in as thin a layer^as possible on a metal surface, it forms, after slow drying, a kind of skin which ensures absolute protection against atmospheric influences. The durability of this covering is said to be mast satisfactory. India-rubber oil is also said to be effective in the removal of rust.

— The evidence is cumulative of the fact that invention and the multiplication of machinery creates an increased demand for labour, instead of having the opposite effect, as is held by many. One invention, or one new machine, opens the way for another, and either very often calls into existence an entirely new trade. Our contemporary, the Wood Worker, speaks of the scroll saw, a very simple instrument, but one which nevertheless has made room for quite a large business for its own manufacture, besides creating many new wants, which calls for an outlay of labour, which would never have been needed had it not been for that little invention. These saw-blades are often of a mere ribbonlike thickness, with teeth invisible to the eye, and perceptible to the touch only. As a dozen blades are supposed to accompany each of the 200,000 machines already in existence, that would have called for the manufacture of over 4,800,000 blades ; and as each sawyer requires them by the dozen, if not gross, owing to their liability to break, the number manf uctuved is simply amazing. The low price at which they are produced is, however, still more astonishing, considering the work required of them. The demand for scrollsjvt patterns also keeps busy a large number of men. Then the demand for fancy woods created by the popularity of the scroll saw is something stupendous, firms having to send their orders at least six months in advance to secure a stock. The sawmills receive the woods in the log from the different sections where they grow. For fancy scroll-sawing, Central and South America supply the rosewoo'l, tulipwood, cocobola, amaranth, and satinwood, and Mexico the mahogany and Spanish cedar. White holly, walnut, oak, and ash are domestic woods. The woods are sawed on veneer saws, and, after drying, are planed to the required degree of thickness — sometimes to one 24th of an inch.

— Is Paper to be the Rail of the Future? — This question is seriously asked by the Boston Journal of Commerce, and answered by that paper as follows : It is weU known that one of the best materials for car-wheels is paper. It is now stated that paper can be utilised for the manufacture of rails, in place of steel, which has almost displaced iron. It is said in favour of the new material that the cost per mile will be less by one-third than that of steel, and it will last much longer, being almost indestructible. There is no expansion or contraction from heat and cold ; consequently no loose or open joints ; and, being so much lighter than steel or iron, the rails can be made longer and connections perfectly solid, making the road as smooth as one continuous rail. The adhesion of the drivers of the engine to this material will be greater than that of steel, consequently the same weight engine will haul a larger load. There will be a great saving of fuel, and the smoothness of the rail will lessen the wear and tear of the rolling-stock. The rails are made wholly and entirely of paper, and so solid that the sharpest spike cannot be driven into them. The action of the atmosphere has no effect on it, will neither rust nor rot, and, with paper wheels and rails of the same material, our palatial trains will elide over the prairies at the rate of 60 miles an hour with as little jolt and jar as on an ocean steamer.

— Among the recent discoveries at Hissarlik, by Dr Schliemann, are the remains of buildings which he supposes to have been temples. Nothing, he says, could better prove the antiquity of the buildings than the fact that they were built of unbaked bricks, and that the walls had been baked after they were laid up, by huge masses of wood piled up on both sides of each wall and kindled simultaneously. Each of the buildings has a vast vestibulum, and each (if the trout faces of the lateral walls is piovided with &ix vertical quadrangular boams, which stood on well-polished bases, tho lower part of which wevo preserved, though, of course, in a calcined state. Dr Schliemann maintains that iv these ancient Trojan temples we may see that the anttx or imrastadcs, which in lattoi' Ilelleuic tomplos fulfilled only a technical purpoao, aorved as an important element of construction, for they were intended

to protect the wall ends and to render them capable of supporting the ponderous weight of the superincumbent crossbeams and the terrace. Similar primitive antes were found in two other edifices, and at the lateral walls of the northwestern gate. It was also discovered that the great wall of the ancient Acropolis had been built of unbaked bricks, and had been baked like these temple walla. According to Dr Schliemann, a similar process of baking entire walls has never been before discovered, and the antce in the Hellenic temples are nothing else than reminiscences of the wooden antce of old, which were of important constructive uso.