“ He carried barometers and boiling-point thermometers to the summits of the highest mountains, and estimated the relative humidity of the atmosphere at different heights, its temperature, the strength of solar radiation, the composition of air and its transparency. Then, following the precipitated moisture, he investigated the temperature of the earth at all depths to which he could drive his thermometer staves, the course, conditions and temperature of streams, rivers, glaciers and lakes, even of the sea. ”

“ His modifications of the thermometer adapted that instrument to many purposes: for ascertaining the temperature of the air he used one with a fine bulb hung in the shade or whirled by a string, the latter form being converted into an evaporometer by inserting its bulb into a piece of wet sponge and making it revolve in a circle of known radius at a known rate; for experiments on the earth and in deep water he employed large thermometers wrapped in non-conducting coatings so as to render them extremely sluggish, and capable of long retaining the temperature once they had attained it. ”

“ SAUSSURE, HORACE BÉNÉDICT DE (1740–1799) , Swiss physicist and Alpine traveller, was born at Geneva on the 17th of February 1740. [1] Under the influence of his father and his maternal uncle, Charles Bonnet, he devoted himself to botany. In 1758 he made the acquaintance of Albrecht von Haller, and in 1762 he published his first work, Observations sur l'écorce des feuilles et des petals. The same year he was chosen professor of philosophy at the academy of Geneva, and retained this chair till 1786. His health began to fail in 1791, when too he suffered great pecuniary losses. ”