Musée d'histoire des sciences de la Ville de Genève

About this audio guide

This guide to the Musee d'histoire des sciences in Geneva opens on the summit of Mont Blanc in 1787, where naturalist Horace-Benedict de Saussure held up a homemade color scale, a cyanometer, to measure the blue of the sky, only to find the sky bluer than any strip on his card. It follows the two decades he spent chasing a theory that darker blue meant purer air. A year later he returned with an improved disc of fifty-two shades and camped for two weeks on a windswept ledge above Chamonix to test it.