Helium

Conservation of the helium resources of the U. S. as an American monopoly for both war and peace purposes is the object of bills to be introduced at the present session of Congress. Dr. S. C. Lind, newly appointed chief chemist of the U. S. Bureau of Mines, sponsors the movement. Dr. Lind and his predecessor, Dr. Richard B. Moore, two of the country's leading authorities on rare gases and earths, speaking last week before the American Institute of Chemical Engineers at Washington, out lined the probable future developments of helium and the Government's program for it. The gas is going to waste in the U. S. at the rate of 500,000,000 cubic feet annually. It occurs as a constituent of the natural gas produced from wells in the Dallas-Fort Worth region of Texas, in Oklahoma and in Kansas. These are, in fact, the only large sources in the world. There is enough gas available to keep filled, ready for service, 200 airships of the size of the navy dirigible Shenandoah. In a very few years airships twice the size of the Shenandoah will be built, predicted Dr. Moore. They will carry enough fuel for a round trip to Europe, and a good-sized load of bombs if necessary. Commercial dirigibles will connect North America with Europe, South America, the Far East. A Government plant at Fort Worth is now producing daily 15,000 cubic feet of helium, 92% pure, at a cost of about 7-c- a cubic foot, and 50,000,000 cubic feet could be extracted yearly from gas in regular use. As helium when originally produced was very rare, costing about $1,700 per cubic foot (a large dirigible requires a million or more cubic feet), the reasons for the present optimism regarding its commercial use are obvious. Before the War probably not more than 15 cubic feet of the isolated helium were in existence. At the close of the War the U. S. had developed the process of manufacture and had a considerable quantity in storage for shipment to the front. All the helium now being produced is utilized by the Army and Navy. Other sources are known to the Government, their location being kept secret. Helium is an inert gas of great light ness and non-inflammability, present in the air in minute quantity. Airships inflated with hydrogen or other gases are subject to the danger of being exploded by anti-aircraft guns or engine accidents; helium is immune to such catastrophes. Helium was first dis covered, in 1868, by Sir J. Norman Lockyer, the astronomer, by spectroscopic analysis, as one of the ingredients of the sun's chromosphere, or outer coat. For a long time it was supposed to be indigenous to the sun only, but in 1895 Sir William Ramsay (1852-1916), the brilliant British chemist, winner of the Nobel Prize in 1904, isolated the element from the earth, shortly after he had similarly found argon, in collaboration with Lord Rayleigh. Later it was discovered by Becquerel, the Curies, Rutherford, Soddy and other experts in radioactivity, that the so-called "alpha particles," little groups of four "protons" and two "electrons" given off regularly by uranium and similar substances in their process of degeneration, are in reality atoms of helium. To isolate helium from uranium in commercial quantities would be impossible, but the more recent discovery that helium is a constituent of natural gas made possible the present-day developments. Its purification is one of the major problems. The best method (used at the Lakehurst, N. J., airship station) is by passing the helium over charcoal at a low temperature, resulting in absorption of extraneous gases, leaving nearly 100% pure helium. Helium can be liquefied by cold, and is easily stored in that condition. A laboratory in Toronto is turning out liquid helium for military purposes.

It is an interesting fact that helium airships using gasoline fuel become lighter and lighter, owing to the loss of water vapor from the combustion of the gasoline. To keep the ship down, helium has to be released to bring the weight nearer to that of air. This has made long flights costly and impracticable. But a method of condensing and retaining the water vapor has been devised which keeps the weight uniform and saves the helium.