Historical information

From label: Remnants of the “J” Apparatus beam balance for the measurement of the mechanical equivalent of heat. The solid object is the rotating magnet the construction of which is illustrated on the cover of \\\"A man Ahead of his Times\\\". Made in the Nat. Phil. Workshop for J experiment.

Physical description

Three components of “J” Calorimeter made of metal and covered in green enamel. One small weight from 33.3 has become detached from string.