Did you know that scientist William Thomson, better known as Lord Kelvin, walked from Chamonix to Saint-Gervais in August 1847 over the Col du Bonhomme. The story is that he met another famous scientist: James Prescott Joule who was on his honeymoon here. Mr. Joule was combining business with pleasure and was doing some scientific experiments in this area. Mr. Joule wanted to measure the difference in temperature of water before and after a waterfall. His expectations were that the water at the top was slightly colder than at the bottom. Joule measured the temperature of the Cascades de Sallanches.
Source: George Johnson, 2011, The ten most beautiful experiments & Wikipedia