Helium
Collier's New Encyclopedia (1921)
a gaseous element. Atomic weight 3.99. Discovered in 1868 by means of the spectroscope, in the sun, by Jannsen and Lockyer, the discovery of terrestrial helium was made later by Ramsay, in the gases evolved from the mineral cleveite. It is widely distributed, but occurs in small quantities. It is present in the air to the extent of about one volume of helium in 250,000 volumes of air, occurs in many minerals, and has been found in the gases from hot mineral springs. Ramsay found that the emanations from radium showed the presence of helium, and it is believed to be the final product of the disintegration of radium. It was considered of purely academic interest until 1915, when the suggestion was made in England that it should be used in place of hydrogen in . Its density is alballoons and airships most twice that of hydrogen, but owing to its chemical inertness and non-inflammability its use for this purpose was thought worthy of consideration. The matter was brought to the attention of the United States Bureau of Mines and this led to the development of the Jefferies-Norton and Linde processes for the extraction of helium from natural gas, which consists mainly of nitrogen, methane and helium. By freezing the gas at a temperature of 318° F. below zero, the other gases become liquified, while helium remains in the gaseous condition, and can be drawn off. A yield of 1 per cent. is considered satisfactory. At the time of the signing of the Armistice, quantities of the gas were loaded on the docks at New Orleans, ready for shipment to France.
What Has Changed in the Last Century
When Collier's wrote this in 1921 helium had only just stopped being "of purely academic interest," and its great promise was as a non-inflammable lift gas for airships. That use effectively died with the rigid airship; today the bulk of the world's helium goes into cooling the superconducting magnets of MRI scanners and particle accelerators, and into semiconductor manufacture and leak detection. Physics moved further still: Kamerlingh Onnes had liquefied helium in 1908, and in 1937-38 Pyotr Kapitza, John Allen and Don Misener found that liquid helium below about 2.17 K becomes a superfluid that flows without viscosity. The American natural-gas extraction the entry describes grew into a national stockpile, the Federal Helium Reserve near Amarillo, Texas, which Congress ordered sold off; repeated global shortages since 2006 have made this once-academic gas a strategic commodity.
Written for this edition, 2026.