tried to make this visit a scientific one. He secured extremely valuable collections of the earthworms, beetles, centipedes, dragon-flies, butterflies, ants, moths, scorpions, Crustacea and the ferns and lichens of the greatest altitudes. He was a man who knew just what was worth collecting, and brought back numerous totally new species. He was able also to collect quite a number of unusual ornaments, weapons and implements made by the tribes of prehistoric days, and choice specimens of volcanic rocks and dust. He had the good fortune to be on the top of a near-by mountain at the time of an eruption of Cotopaxi; he saw its very beginning and observed its progress; and has left us admirable notes of the phenomena.
His observations on mountain-sickness led him to conclude that it was caused by diminution in atmospheric pressure, operating in at least two ways: by lessening the value of the air that can be inspired in any given time, and by causing the air or gas within the body to expand and to press upon the internal organs. In the second case, the effects may be temporary and pass away when equilibrium has been restored between the internal and external pressure.
The publication of his work on Ecuador was recognized by the Eoyal Geographical Society, which made him a fellow, and gave him the "Patron's Medal." The Eoyal Society of Edinburgh made him a fellow and the Italian King made him a Knight of the Order of St. Maurice and St. Lazare. Honorary memberships in geographical and mountain-climbing clubs of Europe and America were thrust upon him.
His experiences in South America convinced him that the aneroid barometer was unreliable at high altitudes, and he published a work on "How to Use the Aneroid Barometer," 1891, and succeeded in causing important improvements in the construction of this instrument.
His extensive observations of glaciers led him to attack those who claimed for glaciers great powers of erosion. He considered them of secondary importance to the great forces of expansion and contraction in the breaking-down of rock structures of the mountains. He conceded that glaciers carried down large quantities of material, but would not concede that they created much of this material. Everywhere he went he set down interesting geological observations.
Whymper's reputation as a mountaineer put him in demand for articles on the Alps. In 1896, at the instance of John Murray, the London publisher, he gathered a great quantity of information into a "Guide-book to Chamonix and Mont Blanc" (206 pp.). This book soon became the standard of its kind. It has had an immense sale, reaching its fifteenth edition in 1910. In 1897 Murray brought out Whymper's "Guide Book to Zermatt and the Matterhorn," which is, if
