SCIENCE, MECHANICAL INVENTIONS, ETC.

New Zealand Herald, Volume XLIV, Issue 13396, 26 January 1907, Page 4 (Supplement)

SCIENCE, MECHANICAL INVENTIONS, ETC.

A NOVEL MOTOR ROAD ROLLER. A novel motor road roller has Inieti invented by Mom. Laffy, Boulogne. As in an ordinary road roller tho machine has the usual three rollers, the front wheel being the steerer and the rear wheels being the drivers. Tho machine is driven by a 9-h.p. single cylinder water-cooled engine. The steering is by means of worm and chains.

AN ELECTRIC BUOY. A series of novel floating lights arc about to bo installed at- the mouth of the River Kibe. They differ from tho ordinary light buoys in the fact that tney will be illuminated by electricity generated by the action of the waves. The buoys are constructed to float on the surface of the water, and the motion of rising and falling with the waves works an ingenious electric machine, which generates the light. If the new buoys prove a success it is probable that they will be largely used in other parts of the world.

WEAVING A YARD A YEAR. The Gobelin tapestry weavers, toiling in a Paris factory that the French Government owns, average in the year from one to three yards of tapestry, according to the fineness of the weave and the intricacy of the pattern These weavers work at hand looms, and they put in the tilling, or weft, with a shuttle held in the left. hand. The back of the tapestry is towards them —a minor shows them its other side. Around their looms are baskets of wool of every shade and colour. New Gobelins you can never buy. The French Government gives them all away to the great people, the salt of the earth.' If was a Gobelin tapestry that France gave to Alice Roosevelt for a wedding gift. BOILING GOLD. Professor H. Moissan ha* been trying some interesting experiments in vapuurising gold in the electric furnace. He finds that, it boils at 2400deg. centigrade, and that 100 to 150 grains can be evaporated in two or three, minutes. By condensing the gold vapour on a cool surface cither filiform masses or cubical crystals can be obtained. It is found that gold, like copper and iron, dissolves a certain amount of carbon when in the liquid state, but this separates out as graphite on cooling. Gold is found to be less volatile than copper. The properties of distilled gold are the same as those of hammered gold, or the melted metal reduced to a fine powder. Professor Moissan has found no indications of an allotropic modification of gold. When an alloy of copper and gold is distilled the vapour of copper comes over first, showing that there is no definite compound. In the case, of alloys of gold and tin the latter metal burns in contact, with air. This tin oxide is found to be of a purple colour, due to a deposit of tine gold on its- surface.

NOVEL DOOR HINGE AND CHECK. A hinge of self-closing type, which is provided with a check that prevents shock of impact of the door on the jamb of the casing, is particularly adapted for service on large, heavy doors. It comprises two leaves, one being secured to the casement of the doorway. This leaf is formed with a cylindrical barrel. .Secured in the barrel is a chamber for oil or the like, used in cushioning the swing of the door. Fitted into this chamber is a cup-shaped piston. The piston is adapted to slide vertically within the chamber, but a pin therein engages a. slot in the piston, preventing the latter from rotating. When the door is closed the valve is first seated and then the piston is pushed downward. while the valve, gradually closes the port. The oil pouring up through this constantly narrowing port serves to cushion the swing of the door. The thread on the pintle rod is double, and of such a pitch that the weight of the door can be utilised in place of a, spring to swing the door to closed position.

DREADNOUGHT No. 2. Dreadnought No. 2. of which the keel plates were laid recently- at Portsmouth Dockyard by Admiral Sir A. L. Douglas, will be an improvement in many respects upon the existing Dreadnought. It has already been reported, on what seems good authority, that her 12iu guns will be of increased length, weight, and power. The •tuns of the first Dreadnought were, about 45ft long and weighed 59 tons. The new ship will have guns slightly over 50ft long and over 60 tons in weight, with a greater penetration than the Dreadnought's weapons. In addition the anti-torpedo armament of small guns mav be strengthened. The size of the new ship will be between 18,000 and 19.000 tons, as against the 17,800 tons of the Dreadnought. The speed will 1)3 about the same, and the ship will befitted with turbine engines, four screws, and two rudders', She is one of three battleships of this year's programme, of which the second is to be laid down shortly at Devonport, and the third to be built by contract. It is not yet known definitely whether the promise of the Cawdor memorandum will be made good, ami whether all three battleships will he completed in two years.

ELECTRIC TRACTION IMPORTANT A VINO PENDING. I At the usual meeting of the Manchester Association of Engineers, what the reader of the paper described as "a new-fledged attribute of the electric motor was dealt with. Mr. Edward H. Johnson, of London, was the expounder, and the title of his lecture was "The Third Function of Electric Traction Motors." The paper was highly technical, but interesting to the electrical engineer. A dynamo electric machine is possessed of two functions in common knowledge: (1) It can absorb energy from an external source, and through its motor function convert it into mechanical power; and (2) it can reverse this operation by absorbing mechanical power, and through its generating function convert that into electrical energy. Mr. Johnson pointed out that what is not so well known is the "third function;" that "electrical energy may thus Be regenerated from a moving car or train and delivered to the trolley, the third rail or the other supply conductors, thence, to pass on and assist the prime supply in creating mechanical power elsewhere. It is this economic attribute of ' passing on' the recovered energy to useful employment outside the car or train developing it that constitutes the ' third function.'" It has practically been wasted hitherto. By using this third ■•■ function great savings in cost and addition!?! safety in working would be secured.

LIFE-SAVING HELMETS. When an ammonia pipe bursts in an ice factory or co:d storage plant, the fact is known instantly. Not only the startling explosion warns the workmen, but the clouds of deadly, poisonous fumes which instantly tifl the place drive every living thing which can do so to make its escape. The principle of tin- submarine diver's outfit has been used in providing a workman's helmet wJiich enables a man to enter a room and work for an entire hour where he could not otnerwise live two minutes. When an ammonia pipe bursts the first thing is to get to the nearest cut-off valve and shut off the flow. This can se'dom be done for the reason that at the first whiff of the deadly gases the man falls senseless, and in a few moments dies. The life-saving device which enables the wearer to walk fearlessly into clanger consists of a tight-fitting helmet '' which rests upon the shoulders and is held securely by straps passing under the arms. A tank on the back of the helmet contains a supply of air to last oik- hour, the air being fed into the helmet, immediately under the nose, and its flow regulated "by a valve. A gauge always shows tile exact amount of the supply. Opposite each ear is an ear-piece which has a sounding diaphragm, which transmits sounds like a telephone receiver. The operator can hear but not talk. Hi; can give signals, however, or in front of the mouth is a tube leading to a whistle which hangs in front of the helmet, by means of which he can give prearranged signals or call for help..