Page:Popular Science Monthly Volume 16.djvu/519

Rh that had preceded it to convey upon a plane surface a general idea of the earth's globular form. In this map the newly discovered continent of America, under the name of "The Land of the Holy Cross," was laid down more fully and accurately than in the preceding map of Ruysch. In the following year, 1512, a Polish geographer, John de Stobnicza, in an introduction to Ptolemy, published a map which I regard as of great interest, as it was, as far as I have been able to ascertain, the first attempt to project the spherical surface of the earth upon a plane. If I am right in this supposition, it was the parent of the mode now in use in all atlases of representing in a map of the world both sides of the globe upon a flat surface by two planispheres, or circular maps joined together, one of which includes Europe, Asia, and Africa, and the other America, North and South. This map was constructed to represent that half of the globe which was unknown to Ptolemy, or substantially what is now known in maps of the world as the Western Hemisphere.

The main object of this interesting map was to show where this newly discovered land was situated, and place it in its true position with respect to the whole globe. The map is but a partial or subspherical projection, being cut off at the seventieth degree north latitude, and at the fortieth degree south latitude. The Continent of America, North and South, is represented as running northwesterly to the center of the map, and as extending from 70° north latitude to 40° south latitude, the shape of the continent as then understood being evidently derived from a chart, not then published, which, from an inscription upon it, is supposed either to have been drawn by Columbus, or under his direction. The breadth and general shape of South America, though rudely given, are remarkably correct. The isthmus separating South from North America is laid down, but exaggerated in length; and a small portion of North America is given, its extension to the west being left undefined. The position which the whole continent occupies as a part of the globe is, as would be expected, not correctly laid down, but, as a conjectural representation of its exact position, the map was for that time ( 1512) a very remarkable production.

I have dwelt upon this map, because it has not received from geographers the attention it deserves; and for the further reason that it furnishes a striking illustration of the slow progress of geographical knowledge; for the projection of maps of the world, upon the same scientific method, did not come into general use until about the beginning of the last century, or nearly two hundred years afterward.

In 1520 Peter Benewitz constructed a map of the world in the form of a heart, after the method of Sylvanus, which has acquired a celebrity as the first map upon which the name of America appears.

In 1531 Oronce Fine undertook to improve this by a projection in the form of a double heart, so as to give, by that method, upon a plane or flat surface, both sides of the globe; and in 1538 Mercator, then a