Werner taught Charpentier, and was a colleague of his father’s. Venetz, a friend and colleague, often met with Charpentier to discuss ideas together; Venetz was at first more persuaded about some puzzling aspects of glacial action than his more sceptical friend. Charpentier hosted Lyell, and later Schimper for a 3-month stay that was crucial in his formalisation of a full theory of glaciation; Agassiz was already there, initially to study fossils not glaciers, while Venetz also visited. Agassiz dedicated his subsequent work on glaciation to Charpentier and Venetz, conveniently forgetting to mention his old friend Schimper’s contribution.