Note 58 — Chapter V · (continued 2)

These conclusions about physical exercise had been previously expounded by Franklin to his son in a letter, dated Aug. 19, 1772, in which he expressed his concern at hearing that William was not well. In that connection they do not seem quite so pedantic. The writer thought that, when tested by the amount of corporeal warmth produced, there was, roughly speaking, more exercise in riding one mile on horseback than five in a coach, more in walking one mile on foot than five on horseback, and more in walking one mile up and down stairs than five on a level floor. He also had a good word to say for the use of the dumb-bell as a "compendious" form of exercise; stating that by the use of dumb-bells he had in forty swings quickened his pulse from sixty to one hundred beats in a minute, counted by a second watch. Warmth, he supposed, generally increased with a rapid pulse. Upon one occasion in France, when John Adams told him that he fancied that he did not exercise so much as he was wont, he replied: "Yes, I walk a league every day in my chamber. I walk quick, and for an hour, so that I go a league; I make a point of religion of it."