National Geographic : 1892 Mar 31
108 Henry Gannett-Mother Maps of the United States. tions determined independently that they have been located. Such determinations have been made in abundance by one means or another, and they are well distributed; so that for maps on small scales there is no difficulty in locating these surveys. As these surveys have been made merely for the purpose of subdividing the land, little attention has been directed toward making them available for the production of maps. The instruc tions under which they have been made, however, require that the points of crossing of all streams by the lines of survey be noted, together with the directions of the streams; that all streams above a certain breadth, as well as the borders of all lakes and ponds, be traversed; and that the limits of all swamps and marshes and timbered lands be noted. Had these instructions been every where carried out a large amount of geographic information would have been gathered; but unfortunately they have not been fully carried out, and hence the township plats differ greatly in the amount of information which they present. These plats are made on a scale of 2 inches to a mile, a scale many times greater than the degree of detail upon them requires. From these plats, with the addition of information from other sources, the General Land office prepares and publishes a series of very useful state and territorial maps on scales ranging from ten to eighteen miles to an inch, and a map of the United States upon a scale of about 40 miles to an inch. There is another group of maps published by the general gov ernment, the material of which is, in the main, compiled, but which contains certain elements of originality. These are the postal-route maps which are prepared by the Post-office depart ment for illustrating the location of post-offices and the lines of transportation of mails. The natural features of these maps are of course compiled. The boundary lines of counties, on the contrary, are in the main laid down directly in accordance with statute. The location of railroads is effected mainly by means of plats furnished directly from the railroad surveys, and the location of post-offices is in a corresponding measure derived from similar sources. With the exception of a few minor matters, the above list covers the survey works and the sources of geographic information furnished by the general government. We turn next to the work done by the various state governments.
1892 May 15
1892 Feb 19