Laboratory Experiments for Physics and Chemistry

The correspondence about Mr. Noakes' criticism that the electrical determination of J is 'illogical or redundant or both' has reminded me that in 1942 I suggested making the joule the unit of heat, and showed how, if mechanical ideas and systems of measurement had been introduced at the beginning, thermodynamics would have been considerably simplified. The measure-system of mechanics can be introduced into any branch of physics provided that, among the phenomena concerned, force is exhibited somewhere. In heat we have the force due to expansion: so by using this force in the case of an ideal gas, we can introduce the erg to define a temperature scale and take the joule as the practical unit of quantity of heat.