A discussion on supraconductivity and other low temperature phenomena

In a discussion of low temperature phenomena it may be assumed that we are dealing chiefly with the properties of materials at temperatures that can be reached by the use of liquid helium. Until 1923 liquid helium had been United States of America, in Canada, in England, in Germany, and in the Soviet Union as well as in Holland. New Methods of Liquefying Helium Since 1932 two notable advances have been made in the design of apparatus for the production of liquid helium. The equipment developed by Simon and Mendelssohn and installed in the Clarendon Laboratory at Oxford represents one of them. Liquid helium is produced at a low cost, but in very small amounts, by a discontinuous process in which the cooling is produced by the adiabatic by Simon and his associates, by the desorption of helium gas from charcoal.