The work was at once distributed among the different members of the party,--Agassiz himself, assisted by his young friend and favorite pupil, Francois de Pourtales, retaining for his own share the meteorological observations, and especially those upon the internal temperature of the glaciers.* (* See "Tables of Temperature, Measurements" etc., in Agassiz's "Systeme Glaciaire". These results are also recorded in a volume entitled "Sejours dans les Glaciers", by Edouard Desor, a collection of very bright and entertaining articles upon the excursions and sojourns made in the Alps, during successive summers, by Agassiz and his scientific staff.) To M. Vogt fell the microscopic study of the red snow and the organic life contained in it; to M. Nicolet, the flora of the glaciers and the surrounding rocks; to M. Desor, the glacial phenomena proper, including those of the moraines. He had the companionship and assistance of M. Henri Coulon in the long and laborious excursions required for this part of the work. This is not the place for scientific details. For the results of Agassiz's researches on the Alpine glaciers, to which he devoted much of his time and energy during ten years, from 1836 to 1846, the reader is referred to his two larger works on this subject, the "Etudes sur les Glaciers," and the "Systeme Glaciaire." Of the work accomplished by him and his companions during these years this slight summary is given by his friend Guyot.* (* See Biographical Sketch, published by Professor A. Guyot, under the auspices of the United States National Academy.) "The position of eighteen of the most prominent rocks on the glacier was determined by careful triangulation by a skillful engineer, and measured year after year to establish the rate of motion of every part. The differences in the rate of motion in the upper and lower part of the glacier, as well as in different seasons of the year, was ascertained; the amount of the annual melting was computed, and all the phenomena connected with it studied. All the surrounding peaks,--the Jungfrau, the Schreckhorn, the Finsteraarhorn, most of them until then reputed unscalable,--were ascended, and the limit of glacial action discovered; in short all the physical laws of the glacier were brought to light."