IN 1916, at the request of the Admiralty, and in collaboration with my colleagues, Profs. Satterly, Burton, and Dawes, I investigated the natural gases of Canada with the view of ascertaining the amount of their helium content. The gases with the highest helium content were found at that time to be in Ontario and in Alberta. In neither Province was any con siderable supply of gas located that contained more than 0.36 per cent, of helium. During the years 1917–1920, with the assistance of Mr. John Patterson, of the Meteorological Office, Toronto, I designed and success fully constructed and operated a semi-commercial plant for extracting helium from natural gas. The gas we worked upon was obtained from an extensive field situated near Calgary, Alberta. During the operation of this plant we extracted in all from 15,000 to 20,000 cubic feet of helium having a purity of 90 per cent. When the Cryogenic Laboratory was instituted in the University of Toronto in 1922, the helium extracted at Calgary became available, and we suc ceeded in liquefying helium early in January 1923.