"N. 4. Horologium Horizontale Ubi Axis Mundanus Supra Horizontem Extollitur Gradus XLVIIII Scrupula XXIIII", Ritter, Franz

Franz Ritter was a German mathematician and astronomer whose works are extremely rare. This beautiful engraving is a horological diagram remarkable for the elaborate decorative border. At top is a large cartouche and at bottom is a 32-point wind rose. The names listed at right and left correspond to various saints on the Julian calendar. A very rare and unusual cartographic curiosity.

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Condition: A

A dark impression on a bright sheet with a small medallion watermark, issued folding and now flattened. Binding trims at left have been professionally replaced, and there is a faint damp stain at far left.