The following is a list of the principal of the passes across the main ridge of the range of Mont Blanc, with the years in which the first passages were effected, as far as I know them:—1. Col de Trélatête (1864), between Aig. du Glacier and Aig. de Trélatête. 2. Col de Miage, between Aig. de Miage and Aig. de Bionnassay. 3. Col du Dôme (1865), over the Dôme du Goûter. 4. Col du Mont Blanc (1868), over Mont Blanc. 5. Col de la Brenva (1865), between Mont Blanc and Mont Maudit. 6. Col de la Tour Ronde (1867), over la Tour Ronde. 7. Col du Géant, between la Tour Ronde and Aigs. Marbrées. 8. Col des Grandes Jorasses (1873), between the Grandes and Petites Jorasses. 9. Col de Leschaux (1877), between the Aig. de l’Eboulement and the Aig. de Leschaux. 10. Col Pierre Joseph (1866), over Aig. de l’Eboulement. 11. Col de Talèfre (1865), between Aigs. Talèfre and Triolet. 12. Col de Triolet (1864), between Aigs. Talèfre and Triolet. 13. Col Dolent (1865), between Aig. de Triolet and Mont Dolent. 14. Col d’Argentière (1861), between Mont Dolent and la Tour Noire. 15. Col de la Tour Noire (1863), between the Tour Noire and the Aig. d’Argentière. 16. Col du Chardonnet (1863), between Aigs. d’Argentière and Chardonnet. 17. Col du Tour, between Aigs. du Chardonnet and Tour. 203 After crossing the glacier de Breney, we ascended by some débris, and then by some cliffy ground, to the glacier which surrounds the peak upon the south; bore to the left (that is to the west) and went up the edge of the glacier; and lastly took to the arête of the ridge which descends towards the south-west, and followed it to the summit (12,727). 204 Manufactured and sold by Messrs. Buckingham, Broad Street, Bloomsbury. 205 For example, when the leader suspects crevasses, and _sounds_ for them, in the manner shown in the engraving, he usually loses half a step or more. The second man should take a turn of the rope around his hand to draw it back in case the leader goes through.