"We see a vast difference between the two qualities of two equal amounts of energy expended by two men, of whom one, let us suppose, is on his way to his daily quiet work, and another on his way to denounce a fellow-creature at the police station, while the men of science see none ; and we, not they — see a specific difference between the energy in the motion of the wind and that of a revolving wheel. p. 89"
January 1, 1970