National Geographic : 1892 Mar 31
112 Henry Gannett-Mother Maps of the United States. upon which it is worthy of being represented, and thus to make an estimate of the area of the country which can be mapped from existing material upon each of several different scales. The scales which I shall consider are 1, 2, 4, 8 and 16 miles to an inch. I exclude from consideration, for the present, the ter ritory of Alaska. On a scale of 1 mile to an inch, I find that only 100,000 square miles can be mapped, or about one-thirtieth of the area of the country (that area being ,a trifle over 3,000,000 square miles). This area possible to map includes the states of Massachusetts, Rhode Island, Connecticut and New Jersey and parts of numer ous other states, mainly in the north. It includes a narrow strip of topography along the sea and lake coasts and the Mississippi and Missouri rivers. Two-thirds of this area is the work of the United States Geological survey, the balance being mainly that of the United States Coast and Geodetic survey. On the scale of two miles to one inch, an area of 360,000 square miles has been surveyed by the Geological survey. No work adapted to representation upon that scale has ever been surveyed by other organizations. This area is widely scattered over the country. On this scale, therefore, an area of 460,000 square miles, or between one-fifth and one-sixth of the area of the country, can be mapped. On a scale of 4 miles to one inch, the work of several organiza tions is included, viz, the exploration of the 40th parallel, the Hayden, Powell and Northern Transcontinental surveys, the Black hills survey, the 4-mile work of the Wheeler survey, and the 4-mile work of the United States Geological survey. The work of these organizations foots up, after deducting the over lapping areas, 460,000 square miles. All this area is in the Cor dilleran region. The area in the United States which can be mapped on a scale of 4 miles to one inch is, therefore, 920,000 square miles, or between one-third and one-fourth of the area of the country. The original maps of this area are all of such character as to furnish material for representing all the three elements of a topographic map-the hydrography, the culture and the relief. They include most of those parts of the country which present high relief, including the southern Appalachians and most of the Cordilleran region. With the exception of 60,000 square miles furnished by the Wheeler survey, the relief of this area can be expressed quantitatively by contours.
1892 May 15
1892 Feb 19