8. The Survey's three small base maps of the United States—(a) a map 18 by 28 inches, scale 110 miles to 1 inch, which is published both with and without contours, or with relief or hypsometric shading; (b) a map 11 by 16 inches, scale 190 miles to 1 inch; (c) a map 71/2 by 12 inches, scale 260 miles to 1 inch, designed for use as a two-page illustration in a bulletin or a water-supply paper.
9. The Century, Rand McNally & Co.'s, Cram's, Stieler's, The Times, Johnston's Royal, and county atlases.
10. State and county maps.
11. Railroad surveys, which are useful in furnishing data for elevations as well as for locations of towns and stations.
12. The latest national-forest maps and proclamations. It is, however, not necessary that national forests, bird reservations, and national monuments be shown on a map in a report unless their addition is specially requested by the author or by the chief of the branch submitting the report, and they should not be shown if they will obscure other more important data.
[2] See "Topographic maps and folios and geologic folios published by the United States Geological Survey" (latest edition).
