THE WONDER OF THE NEW CENTURY.

New Zealand Times, Volume LXXI, Issue 4383, 14 June 1901, Page 2

THE WONDER OF THE NEW CENTURY.

(By George D. Meudell.) I happened to bo in New Orleans when Professor Metz lectured on liquid air and canducted many unique experiments. Tha air had been brought in four vacuum bulbs a distance of 1700 miles, and cost, £2OO. Professor Metz opened by declaring that liquid air wwuld be the chief miracle of the 20th century, and it would be the motive power of this century, as electricity was of the nineteenth. Liquid air has a temperature of 312 deg. below zero. It is procured by complex machinery forcing air through tubes of compression, then around coils immersed in writer, where it receives a reverse action. This process is repeated again and again, until liquid air is finally drawn off. The three cylinders employed were compression pumps, such as are used for pumping up a pneumatic bicycle tire, only they wore worked by steam, and were many hundred times stronger and more powerful. Firstly, the air u compressed to one-tenth Us volume. This compressed and consequently hot air is passed through tubes surrgunded by cold water, to absorb the heat set free by compression. In the second pump a prossura of 10001 b to the square inth is applied. Again the air becomes hot, and is again cooled. In the third pump the pressure is raised to 22001 b to the square inch. Practically, by enormous pressure the heat has been squeezed from tha atmosphere like water from a wet spouge. The compressed gas is passed through a purifier to be filtered foi; dust, aud tha greater part of the remaining moisture is removed uy proper absorbents. The gas, or air, is then passed through a long bent tube. A certain lynount of it is allowed to escape through a valve, and as it suddenly expands it reabsorbs exactly aff much heat as was taken from it. This causes tbo temperature to fall, and the cold air thus derived is used to cool tha outside ci the long tube containing the remainder of the air. Then more air is allowed out of the tube by the valve, and is made to further cool what is left in the tube. Finally a point is reached at which the constituents of the air cannot longer exist in a gaseous state, and liquefaction of the air results. This change takes place at 312 deg. below zero. Vacuum tubes are used to carry it, as it stored in air tight vessels the vessels and contents on wax-ming would exert such pressure as even if built of steel the vessel would bo shattered into molecules. Liquid air is a perfectly transparent liquid, with a pale blue tinge. Some air was tossed on the floor, aud though it hissed and steamed there was no dampness, as it is the driest liquid known to science. Handkerchiefs wore dipped in a bowl of the air, and though they steamed were perfectly dry and quite stiff with cold. Beefsteak, potatoes, and onions were frozen as hard as rocks by a littlq of the air, and could not bo broken with a hammer on an anvil. Even whisky, which is hard to freeze, froze to a stick. Mercury, which is supposed never to freeze, was frozen into a link, with, hooks in the end. A rope was tied in one link and then to a beam in the ceiling. On the other link was hung an anvil. Mercury was frozen to represent a hammer, and used to drive nails in a wooden-block. Hair felt was lighted and then burnt with some liquid air. Steel pens were welded by burning a match, between them in liquid afr, while ice was .forming on the outside. The principle is that whenever a flame is placed in the liquid air the oxygen augments the heat so greatly that it will melt and produce wonderful effects, while the freezing qualities of the liquid air go on just char same. The following experiments wera rapidly ana successfully made:—A spectacular experiment with frozen roses, whiett were rendered brittle, but retained their colour; a rubber ball was bounced, then hardened with air and smashed like glass ; strawberries were frozen, and steel pens welded in the same glass at the same time; a plug was driven into a vessel of the air and quickly blown out, to show the expansive power of the air;i a kettle of liquid air boiled on a caka of ice. steam issuing freely from tha spout. Professor Metz computed there were already 180 uses for liquid air, cither by. itself or from its by-products. One pound! of liquid an - is equal to three pounds of ice. In Boston it is used for running automobiles. In New York it is operating a refrigerator at 20 deg. below zero. It can be used to manufacture ozone—a bleaching agent of power thail chlorine. As a disinfectant ozone has no equal, and will destroy microbes and purify houses. The oxygen can be used in metallurgical operations, for illumination, for chemicals, and in the manufacture of certain acids. The nitrogen can be used to produce ammonia and cyanides ; for tne sick room aud in ventilating, houses, hospitals and theatres. It can h 0 made into an explosive many timflß more powerful than dynamite, and 100 times as cheap. In fact the professor’s list of the services liquid air cad render mankind has no limit of length.