SCIENCE AND INVENTIONS.

New Zealand Herald, Volume LII, Issue 16050, 16 October 1915, Page 4 (Supplement)

SCIENCE AND INVENTIONS.

SOLDIERS' UNIFORMS. Experiments have beerf made in Europe to determine what colour in a soldier s uniform is the least conspicuous to an enemy. Of ten men, two were dressed in light grey uniforms, two in dark grey, two in green, two in dark blue, and two in scarlet. All were then ordered to march'off. while a group of officers remained watching them- The first to disaopear in the landscape was the light grey, and the next, surprising as it may seem, the scarlet. Then followed the dark grey, while the dark blue and green" remained visible long after all the others had disappeared. Experiments in firing at blue and red targets, made at the same time, proved that blue could be more easily seen at a distance than red. AUTOMATIC GUN LOADING. In firing their big howitzers the Germans found that the tremendous noise of the explosion has affected the hearing and nerves of the artillerymen. The enemy have now devised an automatic feeding system for the Bin and 17in weapons. A kind of endless chain, on the principle of a moving-staircase, carries the shells to the gun through an underground passage from the ammunition depot some, distance to the rear. Once the range is found, the gun is laoded and fired automatically, control being exercised by officers from an armoured observation post. Rapidity of fire and increased accuracy are claimed for the new device, which also embraces a novel use of the periscope for aiming purposes. HARD WATER. Do you realise how hard water is hen a boat sails through it at full speed? Water passing at fifty miles an hour is not the limpid liquid we arc accustomed to bathe in. If you put your arm overboard from a hydroplane running fifty miles an hour and strike a wave crest, the probability is that you will break your ifrni or wrist, because at the speed the water has not time to give, or even to change shape, and striking it is like striking so much metal. If a swordsman should enter one of the great hydraulic quarries where a stream of water, under enormous head, is used to wash down hillsides, and attempt to cut into one of those streams, his sword would fly in pieces without being able to penetrate the water. The stream is like 3, bar of iron. WONDERS OF NAVAL GUNNERY. The fire of a naval gun is directed from the fire-control station, a small box on the masts. Here is' the rangefinder—a large telescope, pointed at right angles to its object. This telescope consists of a series of mirrors of various sizes and curves, which catch the ships all round and fix them before the eyes of the officer, who can set his lenseg so that he can gauge the correct angle by a small calculation and can reckon almost the exact space separating him from his opponent. The information is telephoned to the gunner, who directs the telescopic sight attached to his gun on the desired object. This sight magnifies the size of the opponent and brings its characteristics close to the eye. In the meantime the expert officers in the fire-control watch the fall of the shot. Should it miss, delicate instruments tell ljow far the shell was off the target. The correction is made, and the second shot, if not on the spot, ' comes unpleasantly near. BAFFLING BURGLARS. The Krupps Works at Essen have discovered a burglar-proof safe which will " put all burglars to shame." The discovery consists in the production pf a steel which will withstand the attacks of the oxyacetykne flame, and that it will be impossible to burn a hole through the safe with the acetylene flame either in the time at his disposal, or the amount of acetylene and oxygen that the burglar could carry to his base of operations. At a melting test it required one and. a quarter hours of burning, and used up 176 gallons of acetylene and 554 gallons of oxygen to burn a hole 1 9-10 in in diameter and 1 4 lOin deep into the plate. Such an operation did not burn an opening which would allow the hand to be inserted. In order to produce a hole large enough to admit the hand, the operation requires six hours of time, 2400 gallons of acetylene, and 2600 gallons of oxygen. This would require 6001b of raw material for the burglar's operations, besides requiring almost the whole night to burn through a plate two inches thick. FIRST SUBMARINES. Among the historical relics on exhibition in Berlin is the Plongeur-Marine, Germany's earliest submarine. It was invented by a Bavarian named Wilhelm Bauer. The boat is of iron, and dates back to 1850. It was tried at Kiel, but its thin sides were crushed by the pressure of the water, and it remained at the bottom until it was discovered when the fjrst excavations for the Kiel' Canal were being made. The old submarine was then raised and placed in the Naval Museum in Berlin. Old as it is, this submarine is not the first one ever built. References to submarine operations date back to 1372. In 1727 no fewer than fourteen submarine patents had been issued in England. In 1775 H.M.S Eagle was attacked in New York Harbour by a submarine built by David Bushell. 'Sergeant Lee, in charge of the submarine, actually got under the ship, but was unsuccessful in attaching the torpedo to the bottom of the vessel. Between 1795 and 1812 Fulton experimented in France and America, and showed that it was possible to build a vessel which could be navigated under the water. CURIOUS EXCAVATING MACHINE. A very curious machine has been developed in Chicago for land drainage work, which, instead of being mounted I 011 wheels, is provided with a walking mechanism. Long ago it was recognised that wheels, even' when very broad, do not have sufficient bearing surface for a heavy machine that is to be operated on soft ground, and. as a result, the caterpillar type of propulsion was developed. But. it is claimed that in very soft ground the latter tears up the. soil. " "It consists (savs the Scientific -American) of a central turntable, upon which the excavator normally rests, and two shoes, one at each side, which, when the machine is walking alternate with the turntable in taking tin- weight of the machine. The excavator is arranged to turn on the turntable when the shoes or auxiliary platforms." as they are called, are lifted off the ground, and in this way the machine is steered It may change" its direction readily to any desired angle. The mechanism that operates the auxiliarv platforms consists of a. cam shaft, driven through step down gearing from the main engine, and carries at each end a cam of the. general form of a segment. Mounted on each cam is a carrying beam, connected by chains to the auxiliary platform. Each cam is formed with lugs on its periphery, adapted to mesh with similar lugs on the auxiliary platform. When the machine has walked to its work, the auxiliarv platforms at each side arc raised off the ground and locked in that position, after which, the engine is disconnected from the walking mechanism. The machine can then be swivelled about 011 the turntable. and.as the work proceeds the walking mechanism can be put into operation to move the apparatus to a new position It. the turntable of the shoes sink into the ground, it matters little, for when the machine walks it picks its feet off the. ground and does not have to roll out of the hollow*