If the contrary view were to be adopted, if it could be maintained that “glaciers, _by their motion, break off masses of rock from the sides and bottoms of their valley courses_, and crowd along every thing that is movable, so as to form large accumulations of débris in front, and along their sides,”(141) the conclusion could not be resisted, the greater the glacier, the greater should be the moraine. This doctrine does not find much favour with those who have personal knowledge of what glaciers do at the present time. From De Saussure(142) downwards it has been pointed out, time after time, that moraines are chiefly formed from débris coming from rocks or soil _above_ the ice, not from the bed over which it passes. But amongst the writings of modern speculators upon glaciers and glacier-action in bygone times, it is not uncommon to find the notions entertained, that moraines represent the amount of _excavation_ (such is the term employed) performed by glaciers, or at least are comprised of matter which has been excavated by glaciers; that vast moraines have necessarily been produced by vast glaciers; and that a great extension of glaciers necessarily causes the production of vast moraines. Such generalisations cannot be sustained. We descended in our track to the Lac de Combal, and from thence went over the Col de la Seigne to les Motets, where we slept; on July 13, crossed the Col du Mont Tondu to Contamines (in a sharp thunderstorm), and the Col de Voza to Chamounix. Two days only remained for excursions in this neighbourhood, and we resolved to employ them in another attempt to ascend the Aiguille d’Argentière, upon which mountain we had been cruelly defeated just eight days before. It happened in this way.—Reilly had a notion that the ascent of the Aiguille could be accomplished by following the ridge leading to its summit from the Col du Chardonnet. At half-past six, on the morning of the 6th, we found ourselves accordingly on the top of that pass. The party consisted of our friend Moore and his guide Almer, Reilly and his guide François Couttet, myself and Michel Croz. So far the weather had been calm, and the way easy; but immediately we arrived on the summit of the pass, we got into a furious wind. Five minutes earlier we were warm,—now we were frozen. Fine snow whirled up into the air penetrated every crack in our harness, and assailed our skins as painfully as if it had been red hot instead of freezing cold. The teeth chattered involuntarily—talking was laborious; the breath froze instantaneously; eating was disagreeable; sitting was impossible!