Kinnersley’s Thermometer

—An electric air thermometer consisting of a gla ve el enclosing air, and communicating with a tube partly filled with water or other liquid. Two metal rods are led into this tube and a filament of gilt paper or ~ thin wire is suspended between the two rods. When an electric discharge pa es between the rods, the enclosed air is heated and expands which causes a movement in the indicating column of liquid Observations with the instrument show: (1) That the heating effect of a charge in a wire of given length is inversely proportional to the square of the wire’s cro section area: (2) that the total heat evolved is jointly proportional to the strength of the charge and to the fall of pre ure.