Heat

Printer and statesman whose one-fluid theory of electricity introduced conservation of charge and positive and negative, and who proved lightning electrical and invented the lightning rod.

electricity, atmospheric physics, oceanography

English natural philosopher who isolated hydrogen, showed the composition of water, tested the inverse-square law of electricity, and weighed the Earth with a torsion balance.

experimental physics, electrostatics, gravitation

Scottish instrument maker and engineer whose separate condenser, rotative double-acting engine, parallel motion, governor and indicator transformed the steam engine and supplied the problems from which thermodynamics grew.

mechanical engineering, steam power, heat