4to., (10 1/8 x 10 ½ inches). 2 engraved maps of the hemispheres with original hand-color in full, each mounted as a volvelle with metal distance band (slightly toned). Original publisher's half maroon morocco, brown pebbled cloth, lettered in gilt (one or two pale stains). First edition. Showing 6 continents, with political divisions and major cities, rivers, and deserts. Includes 18 diagrams depicting the earth's relationship to the sun and moon, plus a table: "Symbols & Names of the 12 Signs of the Zodiac." Each hemisphere is fixed on a central point by a brass ruler 22 cm. in length; hemispheres rotate on the central point.