The district surveyed by Forbes remained a solitary bright spot in a region where all besides was darkness until the year 1861. Praiseworthy attempts were made by different hands to throw light upon the gloom, but these efforts were ineffectual, and showed how labor may be thrown away by a number of observers working independently without the direction of a single head.

In 1861, Sheet xxii. of Dufour’s Map of Switzerland appeared. It included the section of the chain of Mont Blanc that belonged to Switzerland, and this portion of the sheet was executed with the admirable fidelity and thoroughness which characterizes the whole of Dufour’s unique map. The remainder of the chain (amounting to about four-fifths of the whole) was laid down after the work of previous topographers, and its wretchedness was made more apparent by contrast with the finished work of the Swiss surveyors.

Strong hands were needed to complete the survey, and it was not long before the right men appeared.

In 1863, Mr. Adams-Reilly, who had been traveling in the Alps during several years, resolved to attempt a survey of the unsurveyed portions of the chain of Mont Blanc. He provided himself with a good theodolite, and, starting from a base-line measured by Forbes in the valley of Chamounix, determined the positions of no less than two hundred points. The accuracy of his work may be judged from the fact that, after having turned many corners and carried his observations over a distance of fifty miles, his Col Ferret “fell within two hundred yards of the position assigned to it by General Dufour!”

In the winter of 1863 and the spring of 1864, Mr. Reilly constructed an entirely original map from his newly-acquired data. The spaces between his trigonometrically-determined points he filled in after photographs and a series of panoramic sketches which he made from his different stations. The map so produced was an immense advance upon those already in existence, and it was the first which exhibited the great peaks in their proper positions.

This extraordinary piece of work revealed Mr. Reilly to me as a man of wonderful determination and perseverance. With very small hope that my proposal would be accepted, I invited him to take part in renewed attacks on the Matterhorn. He entered heartily into my plans, and met me with a counter-proposition—namely, that I should accompany him on some expeditions which he had projected in the chain of Mont Blanc. The unwritten contract took this form: I will help you to carry out your desires, and you shall assist me to carry out mine. I eagerly closed with an arrangement in which all the advantages were upon my side.

Before I pass on to these expeditions it will be convenient to devote a few paragraphs to the topography of the chain of Mont Blanc.

At the present time the chain is divided betwixt France, Switzerland and Italy. France has the lion’s share, Switzerland the most fertile portion, and Italy the steepest side. It has acquired a reputation which is not extraordinary, but which is not wholly merited. It has neither the beauty of the Oberland nor the sublimity of Dauphiné. But it attracts the vulgar by the possession of the highest summit in the Alps. If that is removed, the elevation of the chain is in nowise remarkable. In fact, excluding Mont Blanc itself, the mountains of which the chain is made up are less important than those of the Oberland and the central Pennine groups.

The ascent of Mont Blanc has been made from several directions, and perhaps there is no single point of the compass from which the mountain cannot be ascended. But there is not the least probability that any one will discover easier ways to the summit than those already known.

I believe it is correct to say that the Aiguille du Midi and the Aiguille de Miage were the only two summits in the chain of Mont Blanc which had been ascended at the beginning of 1864.[[24]] The latter of these two is a perfectly insignificant point, and the former is only a portion of one of the ridges just now mentioned, and can hardly be regarded as a mountain separate and distinct from Mont Blanc. The really great peaks of the chain were considered inaccessible, and, I think, with the exception of the Aiguille Verte, had never been assailed.