This is the relation of a geological tour in the Alps led by the author, in which three young Edinburgh geologists took part. Their goal was to see, on the spot, evidences of thrusting. From Geneva to Sion they crossed two Nappes of the Pre-alps and three Nappes of the High Calcareous Alps. The party travelled light on foot, with a porter called Cola, a chamois hunter. They visited the Savoy Alps between the Lake of Geneva and the Giffre river. They climbed Mont Buet and went to Les Granges de Salvan, a small summer resort, where by good luck they met Professor James Geikie. Then the party went on to Salanfe, a splendid corrie at the foot of the Dents du Midi. They studied the core of the Morcles Nappe in the great wall of the Tour Sallière...