"A MOVABLE PLANISPHERE, Showing the positions of the heavens at any given time"

A planisphere can also be known as a "Star Chart". It is a tool used to identify the stars and constellations you can see in the night sky at a specific time and location. A rotating disk that is layered over a map of the constellations and stars allows you to line up the markers on the rotating disc to a specific date and time on the map.  This planisphere was made by Henry Whitall, of Philadelphia. It was originally printed at E.H. Coggins Engraver and Printer at 30 8th Street in Philadelphia (Modern Day Market and 8th in Center City) for the "Mason Brothers" at 108 and 110 Duane St, New York (Modern day TriBeCa). Whitall began making planispheres in 1856. This 4th edition planisphere dates somewhere between 1873 (when the third edition was released) and Henry Whitall's death in 1883.  Today, the existing remaining planispheres are highly sought after by collectors and museums alike. The Smithsonian Institution holds a version of the second edition of this artifact.  Our planisphere