The district includes a mass of valleys which vie with each other in singularity of character and dissimilarity of climate. Some the rays of the sun can never reach, they are so deep and narrow. In others the very antipodes may be found, the temperature more like that of the plains of Italy than of alpine France. This great range of climate has a marked effect on the flora of these valleys: sterility reigns in some, stones take the place of trees, débris and mud replace plants and flowers: in others, in the space of a few miles, one passes vines, apple, pear and cherry trees, the birch, alder, walnut, ash, larch and pine alternating with fields of rye, barley, oats, beans and potatoes. The valleys are for the most part short and erratic. They are not, apparently, arranged on any definite plan: they are not disposed, as is frequently the case elsewhere, either at right angles to, or parallel with, the highest summits, but they wander hither and thither, taking one direction for a few miles, then doubling back, and then perhaps resuming their original course. Thus long perspectives are rarely to be seen, and it is difficult to form a general idea of the disposition of the peaks. The highest summits are arranged almost in a horse-shoe form. The highest of all, which occupies a central position, is the Pointe des Écrins; the second in height, the Meije, is on the north; and the Mont Pelvoux, which gives its name to the entire block, stands almost detached by itself on the outside. At the beginning of July, 1861, I despatched to Reynaud from Havre blankets (which were taxed as “prohibited fabrics”), rope, and other things desirable for the excursion, and set out on the tour of France, but four weeks later, at Nimes, found myself completely collapsed by the heat, then 94° Fahr. in the shade, so I took a night train at once to Grenoble. I lost my way in the streets of this picturesque but noisome town, and having but a half hour left in which to get a dinner and take a place in the diligence, was not well pleased to hear that an Englishman wished to see me. It turned out to be my friend Macdonald, who confided to me that he was going to try to ascend a mountain called Pelvoux in the course of ten days, but on hearing of my intentions agreed to join us at La Bessée on the 3d of August. In a few moments more I was perched in the banquette _en route_ for Bourg d’Oysans, in a miserable vehicle which took nearly eight hours to accomplish less than thirty miles.