Topographic maps. Illinois. Illinois, Dunlap quadrangle, lat. 40°45′-41°, long. 89°30′-89°45′. Scale 1:62,500, contour interval 20 ft.
Publication Title:
Illinois. Illinois, Dunlap quadrangle, lat. 40°45′-41°, long. 89°30′-89°45′. Scale 1:62,500, contour interval 20 ft.
Display Title:
Topographic maps. Illinois. Illinois, Dunlap quadrangle, lat. 40°45′-41°, long. 89°30′-89°45′. Scale 1:62,500, contour interval 20 ft.
Corporate Agency Authors:
Geological Survey and Interior Department
Sort Author:
Geological Survey
Date:
edition of 1937
Publish Date ISO Format:
1937-01-01T00:00:00Z
Publication Start:
19370101
Publication End:
19371231
Corporate/Agency Author:
Geological Survey
Publication month:
13
Publication year:
1937
Publication place:
Washington
Printer:
Geological Survey
SuDoc number:
I 19.12:12 D 921/3
Description:
17.5X13.3 in.
Notes:
NOTE.—The Geological Survey is making a series of topographic maps that will eventually cover the whole United States, also Alaska, Hawaii, and Puerto Rico. The individual maps are projected to represent quadrangle areas rather than political divisions, and each map is designated by the name of some prominent town or natural feature in the area mapped. The scales most commonly used are 1:31,680, 1:62,500. and 1:125,000. corresponding approximately to ½ mile, 1 mile, and 2 miles to 1 inch. The area covered differs with the latitude, but the average area of a quadrangle is 58 and 230 and 920 square miles, respectively, for these three scales. Topographic maps are printed on uniformsized paper, about 20 by 16½ inches, and the maps of the quadrangle areas represented thereon are about 17½ inches long and 12 to 15 inches wide, according to latitude. For some areas of particular importance special large-scale maps are published. A general description of topographic maps and a list of the symbols used are printed on the reverse of ench sheet.
About 47 percent of the continental area of the country, excluding Alaska, has been mapped, every State being represented. Connecticut, Delaware, the District of Columbia. Hawaii, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Ohio, Rhode Island, and West Virginia are completely mapped. A number of the topographic maps covering 15′ quadrangle areas in New Jersey are out of print, the Survey not reprinting these as the stocks become exhausted but referring applicants to the Department of Conservation and Development, at Trenton, which publishes maps on a slightly different scale (1:63.360) representing approximately two and a half times the area of the Federal quadrangles. Maps of the regular size are sold by the Geological Survey at 10c. each. Except as otherwise indicated, a discount of 40 percent is allowed on any order which amounts to $5.00 at the retail price. The discount is allowed on an order for either maps or folios alone or for maps and folios together.