[Ritter Sundial Map of the World]

This highly unusual map projects the world from the north pole as though it were the table of a sundial, with the land masses drawn to scale in proportion to their distance from this point. The map is thus highly distorted according to normal conceptions but it is nevertheless mathematically correct. The engraving is clear and neat, within a rectangular floral frame. Embellished with a 16 point compass rose in the style of the 16th Century Lafreri maps, with the names of the winds shown.

This map is from Speculum Solis in the second state of 1640.

Projected from the North Pole, the map covers about three fourths of the sphere, extending south as far as Patagonia and southern Madagascar, both of which run off the map. The continents appear wildly distorted by common convention due to the map's unusual projection, in which the scale adjusts according to distance from the North Pole. Consequently, the further a landmass is from the North Pole, the larger it appears. Here, the continents of the Southern Hemisphere, Africa and South America, dominate the page.

Only limited parts of North America are present, but the St. Lawrence is readily identifiable, as is Florida. South America is large and richly illustrated with substantial content derived from Sir Walter Raleigh. Both the Orinoco River and the Amazon river are shown, with a vast inland sea, Lake Parima (Parime Lacus).
Further south, another great inland sea appears connecting the Amazon and the Paraguay (Payana) Rivers.

The map also offers a richness of illustrations including blemmyes (men with heads in their chests) or Raleigh's Ewaipanoma, a leopard, a turtle, a large snake and a long-eared goat in South America.
There are elephants illustrated in southern Africa. The oceans are alive with a wealth of sea creatures, including a sea dog and what appears to be a janus-finned mer-person. A labeled wind rose is situated at bottom center.

Ritter introduced this projection in the 1607 edition of his "Speculum solis; das ist, Sonnenspiegel". That example was simplified, much smaller, and incorporated into sheet with ten horological diagrams. Having attracted some interest, the map was subsequently elaborated upon and enlarged to a full page for the 1610 edition of the Speculum Solis. It was engraved by P. Troeschel in Nuremberg. There are two states of the map, the 1610 first state, and this, the 1640 second state. Other than the imprint, there are no substantial differences between states.

According to Snyder in volume III of the History of Cartography:
The gnomonic projection has a direct connection with sundial design. The angles between the hour markings on a sundial designed for a particular latitude are identical with the angles between the meridians on a gnomonic projection centered at the same latitude, counting each 15 degrees of longitude from the central meridian as one more hour from noon. To allow one to read time, the gnomonic map is first rotated so that the north pole is south of the center of projection rather than north. Then the triangular gnomon of the sundial is placed with its base along the central meridian and its shadow-casting back touching the north pole on the map. The local sun time is indicated by the meridian along which the shadow of the sun then falls.

Ritter was an astronomer and cartographer, perhaps best-known his 'sundial' world map. Ritter specialized in the design and manufacture of astrolabes, sundials, and other scientific instruments.

Reference: Shirley, World 110.