A polymath, Saussure was a founder of geology (a word he coined) and of alpinism. He collected plant specimens for Haller, his mentor and friend. Bonnet got him to train for his ascent of Mont Blanc by climbing the stairs 8 or 9 times daily. He helped fund the Montgolfiers, and took temperature-readings inside their balloon. Volta inspired him. He met Guyton de Morveau in Dijon, Buffon in Paris, Franklin in London, and dined with Banks the evening before Bank’s departure on Cook’s voyage. Humboldt visited, after one of his cyanometers, and Jefferson offered him a post in Virginia when he’d fallen on hard times.