XXXV + 

This accident was after all a great benefit to the geological department of my journey, because it taught me the exact height of my room above the alluvial deposits on which the City of Turin is built. My heart beat violently, and I counted quite three beats and a half from the moment when I spurred my horse till I heard the noise made by my slipper, which had fallen into the street, and having calculated the time which heavy bodies take to fall, and that which the waves of sound required in coming from the street to my ear, I fixed the height of my window at eighty-four feet three inches and nine-tenths of an inch above the pavement of Turin, on the supposition that my heart, excited by the dream, beat 120 times in a minute, which cannot be far out. It is only as a pure matter of science, after having dilated so much on my fair neighbour’s interesting slipper, that I could venture to speak of my own also, and I foresee that this chapter will after all please none but philosophers. + 