Journey from London and French countryside. Towns and Paris are vastly improved since 1801 visit. Charles Babbage and wife are in Paris. Received letters of introduction from Georges Cuvier, J. N. Nicollet, and J. P. Delessert for JH's expedition to Auvergne. Alexis Bouvard is recovering from fall. Georgianna Babbage has recovered and promised to write to MPH. [Letter continued 4 Sept. in Moulins:] Traveled more than 100 miles today. [Letter continued 5 Sept. in Clermont-Ferrand:] Massive flooding in Riom. Impressive view of volcanoes. [Letter continued 6 Sept.:] Will ascend Puy de Dôme today with two companions.