It is not so easy to understand how Dr. Tyndall and Bennen overlooked the existence of this cleft, for it is seen over several points of the compass, and particularly well from the southern side of the Théodule pass. Still more difficult is it to explain how the Professor came to consider that he was only a stone’s-throw from the summit; for, when he got to the end of “the shoulder,” he must have been perfectly aware that the whole height of the final peak was still above him. 70 Dr. Tyndall ascended the Matterhorn in 1868. See Appendix *F*. 71 Information upon the Val Tournanche will be found in De Saussure’s _Voyages dans les Alpes_, vol. iv. pp. 379-81, 406-9; in Canon Carrel’s pamphlet, _La Vallée de Valtornenche en 1867_; and in King’s _Italian Valleys of the Alps_, pp. 220-1. 72 I shall speak again of this mountain, and therefore pass it over for the present. 73 See the Map of the Matterhorn and its Glaciers. 74 My attention was directed to this note by Mr. A. Adams-Reilly. 75 The summit of the Théodule pass is 10,899 feet above the sea. It is estimated that of late about a thousand tourists have crossed it per annum. In the winter, when the crevasses are bridged over and partially filled up, and the weather is favourable, cows and sheep pass over it from Zermatt to Val Tournanche, and _vice versa_. In the _middle of August, 1792_, De Saussure appears to have taken mules from Breil, over the Val Tournanche glacier to the summit of the Théodule; and on a previous journey he did the same, also in the middle of August. He distinctly mentions (§ 2220) that the glacier was completely covered with snow, and that _no_ crevasses were open. I do not think mules could have been taken over the same spot in any August during the past twenty years without great difficulty. In that month the glacier is usually very bare of snow, and many crevasses are open. They are easily enough avoided by those on foot, but would prove very troublesome to mules. A few days before we crossed the Breuiljoch in 1863, Mr. F. Morshead made a parallel pass to it. He crossed the ridge on the _western_ side of the little peak, and followed a somewhat more difficult route than ours. In 1865 I wanted to use Mr. Morshead’s pass (see p. 235), but found that it was not possible to descend the Zermatt side; for, during the two years which had elapsed, the glacier had shrunk so much that it was completely severed from the summit of the pass, and we could not get down the rocks that were exposed.