The summer of 1836 was an eventful one for Agassiz,--the opening, indeed, of a new and brilliant chapter in his life. The attention of the ignorant and the learned had alike been called to the singular glacial phenomena of movement and transportation in the Alpine valleys. The peasant had told his strange story of boulders carried on the back of the ice, of the alternate retreat and advance of glaciers, now shrinking to narrower limits, now plunging forward into adjoining fields, by some unexplained power of expansion and contraction. Scientific men were awake to the interest of these facts, but had considered them only as local phenomena. Venetz and Charpentier were the first to detect their wider significance. The former traced the ancient limits of the Alpine glaciers as defined by the frame-work of debris or loose material they had left behind them; and Charpentier went farther, and affirmed that all the erratic boulders scattered over the plain of Switzerland and on the sides of the Jura had been thus distributed by ice and not by water, as had been supposed. Agassiz was among those who received this hypothesis as improbable and untenable. Still, he was anxious to see the facts in place, and Charpentier was glad to be his guide. He therefore passed his vacation, during this summer of 1836, at the pretty town of Bex, in the valley of the Rhone. Here he spent a number of weeks in explorations, which served at the same time as a relaxation from his more sedentary work. He went expecting to confirm his own doubts, and to disabuse his friend Charpentier of his errors. But after visiting with him the glaciers of the Diablerets, those of the valley of Chamounix, and the moraines of the great valley of the Rhone and its principal lateral valleys, he came away satisfied that a too narrow interpretation of the phenomena was Charpentier's only mistake. During this otherwise delightful summer, he was not without renewed anxiety lest he should be obliged to suspend the publication of the Fossil Fishes for want of means to carry it on. On this account he writes from Bex to Sir Philip Egerton in relation to the sale of his original drawings, the only property he possessed. "It is absolutely impossible," he says, "for me to issue even another number until this sale is effected. . .I shall consider myself more than repaid if I receive, in exchange for the whole collection of drawings, simply what I have expended upon them, provided I may keep those which have yet to be lithographed until that be done."