Most of the statements current in 1861 respecting these mountains had been derived from two authors(16)—M. Elie de Beaumont and the late Principal J. D. Forbes. Their works, however, contained numerous errors in regard to the identification of the peaks, and, amongst others, they referred the supremacy to the Mont Pelvoux, the highest point of which they termed the Pointe des Arcines, or des Ecrins. Principal Forbes erroneously identified the high peak seen from the valley of St. Christophe, with that seen from the valley of the Durance, and spoke of both as the Mont Pelvoux, and M. de Beaumont committed similar mistakes. In point of fact, at the time when M. de Beaumont and Forbes wrote their respective memoirs, the proper relation of the Mont Pelvoux to the neighbouring summits had been determined by the engineers employed on the survey for the map of France, but their observations were not then accessible to the public, although they had evidently been seen by M. de Beaumont. This party of surveyors, led by Captain Durand, made the ascent of Mont Pelvoux from the side of the Val d’Ailefroide—that is, from the direction of Val Louise—in 1828. According to the natives of the Val Louise, they got to the top of the second peak in height, and remained upon it, lodged in a tent for several days, at a height of 12,904 feet. They took numerous porters to carry wood for fires, and erected a large cairn on the summit, which has caused the name of Pic de la Pyramide to be given to their summit. In 1848, M. Puiseux made the ascent from the same direction, but his Val Louisan guide stopped short of the summit, and allowed this courageous astronomer to proceed by himself.(17) In the middle of August 1860, Messrs. Bonney, Hawkshaw, and Mathews, with Michel Croz of Chamounix, tried to ascend the Pelvoux, likewise from the same direction. These gentlemen spent several days and nights upon the mountain; and, encountering bad weather, only attained a height of 10,430 feet. M. Jean Reynaud, of whom mention has been made in the preceding chapter, accompanied the party of Mr. Mathews, and he was of opinion that the attempt had been made too late in the season. He said that the weather was usually good enough for high mountain ascents _only_ during the last few days of July, and the first ones of August,(18) and suggested that we should attempt to ascend the mountain in the following year at that time. The proposition was a tempting one, and Reynaud’s cordial and modest manner made it irresistible, although there seemed small chance that we should succeed where a party such as that of Mr. Mathews had been beaten.