Note 62 — IV.[34] CARNOT’S THEORY OF THE MOTIVE POWER OF HEAT.[35] WITH NUMERICAL RESULTS DEDUCED FROM REGNAULT’S EXPERIMENTS ON STEAM.[36]
Robert Henry Thurston translation
The best figure (1896) is J = 778 ft.-lbs. = 1 B.T.U., or J = 426.8 kgm. = 1 calorie, and probably with great accuracy.