MEMOIR 



OF 



JAMES PRESCOTT JOULE, 



i 89 i. 



CHAPTER I. 



INTRODUCTION. — The Mechanical Foundation of PJiysical 

 Science. — ' Matter, Living Force, and Heat! — State of 

 the Language and Knowledge of Physical Science 

 in 1838. — No Recognised Measure of Mechanical 

 Effect. — The Materiality of Heat. — Mechanical Origin 

 of Heat. — Contrary Evide?ice of the Condensing Steam 

 Engine. — Dependence of the Work Developed on Tempera- 

 ture. — Carnofs Law. — The Locomotive Obtrusive. — 

 Suggestions as to Conversion of Heat into Work ; Sequin y 

 Mayer, and Colding. — Chemical and Physical Effects. — 

 Discoveries of Oersted, Sturgeon, Ohm, and Faraday. — 

 Invention of Electro - Magnetic Engine. — Evidence of 

 Convertibility of Heat and Work not Recognised. 



The three laws, the law of conservation of momentum, 

 discovered by Newton, the law of conservation of the 

 chemical elements, discovered by Dalton, and the law of the 

 conservation of energy, discovered by Joule, constitute a 

 complete mechanical foundation for physical science. The 

 discoverer of a law is he who first generalizes whether he 

 has or has not taken part in the discovery of the facts on 

 which the generalization is made. Newton, Dalton and 



