Page:Popular Science Monthly Volume 43.djvu/269

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HE most prominent features in Sir Archibald Geikie's geological work are his studies of the effects of volcanic force, beginning in Scotland and extending to many countries; and his explanations of the fundamental part which geological processes have played in shaping the topographical features of the land, and in the origin of natural scenery.

Prof. Geikie was born in Edinburgh in 1835; was educated at the high school and the university in that city; was appointed an assistant on the Geological Survey of Scotland in 1855; acquitted himself so well in that capacity that when the Scottish branch of the survey was made a separate establishment in 1867, Sir Roderick Murchison appointed him its director. In December, 1870, he was appointed to the new professorship in the University of Edinburgh of Geology and Mineralogy, founded by Sir Roderick Murchison, with a concurrent endowment by the crown. He held this position till the beginning of 1881, when he resigned it, to take the place of Sir Andrew C. Ramsay as Director-General of the Geological Survey of the United Kingdom, and Director of the Museum of Practical Geology in London.

The published record of Prof. Geikie's life relates exclusively to his investigations, papers, addresses, and books on subjects relating to geology. In this field he has labored with unceasing diligence, and to it he seems to have devoted the whole energy of his active career. Complicated problems presented themselves to him when he entered upon the surveys, of which he was called upon to work out the solutions. One of the first to attract his attention was the relation of the crystalline rocks of the Highlands to the Silurian strata on which they rest, which Murchison had accepted as normal; an assumption from which logically followed the hypothesis that these gneisses were altered sediments. Mr. Geikie gradually became dissatisfied with this view, and commissioned two assistants to review the fields in which the most decisive evidence was to be obtained, instructing them "to divest themselves of any prepossession in favor of published views, and to map existing facts in entire disregard of theory." From the evidence afforded by this survey, Murchison's view was proved to be a mistaken one; and for it was substituted the theory that the elevation of the mountains and the metamorphism of the gneisses were the effect of enormous pressure resulting in the folding and breaking of the whole border of the dry land. The mountains have been reduced to their present shape by denudation, by which also much of the evidence of plication has been washed away, while the remains of the disturbed rocks occupy the position