Bakerian lecture.—The nadir of temperature, and allied problems. 1. Physical properties of liquid and solid hydrogen. 2. Separation of free hydrogen and other gases from air. 3. Electric resistance thermometry at the boiling point of hydrogen. 4. Experiments on the liquefaction of helium at the melting point of hydrogen. 5. Pyro-electricity, phosphorescence, &c

Abstract

Details are given in this paper which have led to the following results:— The helium thermometer which records 20º·5 absolute as the boiling point of hydrogen, gives as the melting point 16° absolute. This value does not differ greatly from the value previously deduced from the use of hydrogen gas thermometers, viz., 16º·7.