NOTES ON SCIENCE, MECHANICAL INVENTIONS, ETC.

New Zealand Herald, Volume XXIX, Issue 9028, 5 November 1892, Page 12 (Supplement)

NOTES ON SCIENCE, MECHANICAL INVENTIONS, ETC.

ONE HUNDRED AND FIFTY MILES AN HOUR BY RAILROAD. A new railway is projected on which, instead of trains, single cars of great length will be propelled by electricity, supplied to them through tho rails. The speed to be attained is from 120 to 150 miles an hour. To provide against accidents the roadway is to be built on solid masonry, without curves, steep gradients being adopted instead, if necessary. The great momentum of tho cars will enable them to climb grades which would be insurmountable to a steam locomotive. As a further safeguard, the signalman will have the power to stop the cars by shutting off the current in their section of track. The first experimental line is projected botweon Vienna and BudaPesth. THE FASTEST STEAMER. The model of the new steamer building at Glasgow will, it is claimed, ensure the quickest possiblo transit of the Atlantic Ocean attainable by steam craft. With a length of G3O feet and 70 feet beam, very fine lines are obtained, and the twin screws are of some twenty-three feet diameter, well supported. There are four funnels, and about two hundred foot of the length of the ship i 3 devoted to the boilers and bankers. The engines, triple compound, with four cylinders working four cranks, are figured at 33,000 horse power. Accommodation is provided for some 700 first and 300 secondclass passengers and about 400 emigrants, and all tho arrangements worked out in the plans for carrying out this important feature are far ahead, it is claimed, of anything yet produced in nautical construction. Tho plating of the slttp is carried up to the promenade deck, which runs from end to end, and about twenty fcob on each sido is left for walking. WONDERFUL ENGINEERING WORK. Official details of the great dam at Beetaloo, Australia, correct some of the previously published statements and figures, and tho immensity of sucb a piece of engineering work may well challenge comparison with anything of the kind in that part of the world. The structure is of concrete 110 feet high from tho bed of the creek to the cop of the dam and 580 foot long, being curved in plan to a radius of about 1400 feet; the width of the top is 14 feet, the profile of the section being designed in accordance with Rankine's rules and the width of the section at tho foundation is' 110 feet; the crest of the by wash, which is •200 feet wide, is five feet below the crest of the dam ; and the reservoir behind the dam is full one and a-quarter miles long, with an average width of eight chains. The capacity under these conditions is 800,000,000 gallons, for the supply of a district covering an area of 1700 square miles, including eight separate townships, etc. The quantity of concrete used was 60,000 cubic yards, the net time occupied in construction being about two and a-half years. Special machinery was used for mixing the concrete and depositing it in place, and the whole work is regarded as a most creditable achievement. THE LATEST NEW EXPLOSIVE. A new explosive compound is being developed by Prof. Silas R. Divine, chemist to tho Rand Drill Co., and well known as the inventor of rackarock. Its peculiar virtue, says the Engineering News, is that it is not exploded by concussions of even the most violent character, but yields readily when a fulminate of mercury detonator is applied. In appearance the explosive is a yellowish powder of high specific gravity. It does not deliquesce and does not have either picric acid or nitrate of ammonia as its active principle. In some recent experiments quantities of tho new explosive were placed on a rock and pounded with a heavy sledge-hammer without causing explosion. A shotgun was loaded with a powder charge, and on top, separated only by a thin paper, a-half ounce of the new explosive was placed. Tho gun was fired aD a wooden box and portions of the explosive were found embedded in a scantling inside tho box. An old lb-pdr. cannonade was next charged with IMb of black, blasting powder, and a shell made of linen and tarred cord was filled with 31b 9oz of the new explosive and fired vertically in tho air. The shell was arranged with a time fuse terminating in a fulminate of mercury detonator. When fired the shell rose to an altitude of about '2000fb and was exploded by tho fulminate at that altitude. In another experiment two pieces of lsin iron pipe about 7in long wero each filled with the new explosive and buried in the earth sido by side. One of the tubes contained a fulminating cap ; the other did not. The first tube was exploded and torn into small bits. The tube besido it was split open and badly smashed, but the explosive which it contained was unaffected. These results indicato that tho new explosive may bo of especial value for military purposes, as it may solve tho problem on which Dr. Justin has long been labouring, and with no small success, of firing shells containing a high explosive with ordinary powder. Taking the energy of No. 1 dynamite as 100, the energy of this explosive is 86 per unit of weight or 138 per unit of volume. The high specific gravity makes it especially suitable for packing shells and bore-holes, as great power is concentrated in a small space. It is nob expensive or dangerous to make in comparison with other high explosives. It does not appear liable to injury or change in character from extreme cold or moderate heat, but, like all forms of powder, is nonexplosive when wet. It is proposed to call the new explosive Randite. THE ROSE CAS PROCESS. The Rose fuel gas apparatus now in operation at West Chester, Pa., makes in one hour as much gas as was made formerly in 12 hours, a recent test showing 23,500 cubic feet in an hour's time. The two holders now in use have a capacity of '21,000 and 5,"),000 cubic feet, but the machinery is only run several hours alternate days, as the green gas has to bo exhausted from one holder to the other at a rate of about 4000 feet per hour, though machinery will shortly be installed to exhaust 14,000 or 15,000 feet per hour. In a separate building is stored about 8000 gallons of crude oil, which is used in the manufacture of gas at the rat* of about 32 gallons per 1000 cubic feet of gas. The oil is pumped to a tank on thf roof of the building, from whence, by gravity, it goe3 to the furnaco and mingles with the coke. But one man is now employed, who does the work formerly done by four or five men. An expert from Philadelphia made a test of tho gas a few days ago, and reported that candle power was 302 and the specific gravity '000, and tho heat units per foot 689. Only four gallons of crude oil per 1000 feet were used. This gas is being sold for fuel purposes at 75 cents per 1000 feet where the consumer uses more than 5000 feet per month. Tho cost of it with coal at 2dol. 90 cents and coke at 3dol. 80 cents per ton and oil at 2;| cents per gallon, is 20 cents per 1000 feet delivered in tho holder. The Rose process is new in several respects. Steam is decomposed with bituminous coal enriched with crude oil, and the gas is fixed with red-hot coke. The product is not strictly a water-gas, as ib only contains about nine per cent, of carbonic oxide. It is very rich marsh gas hydrogen, hence its high heating power. One man is managing the West Chester machine and producing gas at the rate of 20,000 feet per hour. COAL-CUTTING BY MACHINERY. The undercutting of coal by machinery is now claimed to bo greatly facilitated by means of a newly designed arc apparatus, involving, it is asserted, a decided improvement on the>ußual principle of construction in vogue. A heavy iron base, cast in one piece, serves as a foundation for all the parts, carrying two pairs of axles, one at right angles with the other ; the gauge of one pair is fixed to suit the regular track gauge of the mine in which tho cutter is to work, and these axles carry small-flanged wheels upon which the cutter is easily moved about the mine, and in and out, according to requirement. Tho second pair of axles carry small wheels for supporting the cutter when in actual operation and carrying it along the face of bhe wall being cub ; they are not flanged, bub kept on the track by two pairs of single and two pairs of double guides, and the support of the machine is easily changed from one pair of axles to the other by means of a cam worked by screws, the larger-flanged wheels being raised out of the way when the cutter is moving. The motor power is furnished by a 15 h.p. motor, which is perfectly watertight and thoroughly protected from all danger of mechanical injury.' The armature shaft carries a bevelled gear, thus giving the shaft on the right a right-handed or left-handed rotation, and, by an ingenious arrangement, this shaft operates the feed chain at practically any desired speed.