Geographic data indicating device - comprises two superposed discs rotatable about common axis, one provided with apertures and other displaying data

摘要

The geographical data disc is composed of two superposed circles which can be rotated around their common centre(6). One of them, the mask(2) is smaller than the other, the base(4). Data is inscribed on the base disc(4). Windows are provided in one half of the smaller disc as well as a peripheral index(10). On a peripheral border(8) of the base disc are the names of continental countries. To obtain information about a country, the mask disc(2) is turned so that the index(10) is opposite a mark in the middle of the name of the country. The geographical data for the country then appears in the windows.