Geological Work in the United States

Abstract

THE work of the Geological Survey of the United States is in many regions also geographical. Bulletin No. 307 (1906), by Henry Gannett, is thus a useful “Manual of Topographic Methods,” reviewing in its eighty-six pages “the most approved methods of surveying as applied to the production of topographic maps.” Those of us who have used the American maps on the scale of 1:62,500 may have wondered at the selection of this figure in place of our 1: 63,360, or 1 inch to one mile. It is here clear, however, that the American scale is a convenient deduction from i: 250,000, which is employed for the maps of large areas, and which furnishes a scale of practically four miles to an inch. The thick Bulletin No. 299, by Mr. Jas. McCormick, is a second edition of the “Geographic Dictionary of Alaska,” and includes 9300 names, as against 6300 published in 1902, numbers that afford “a rough indication of Alaskan growth.”