Instrument for transits by Stackpole, 1874
Object notes Associations
This elegant little instrument is marked "Stackpole & Brother New York 1522." It was made for American observers of the Transit of Venus of 1874. New it cost $215. The U.S. Naval Observatory transferred it to the Smithsonian in 2005.
The instrument was apparently made with two top assemblies, and so could be used in two different ways. With a telescope mounted in wyes, it would measure horizontal angles. With another telescope attached to a vertical circle, it would measure horizontal and vertical angles. In this example, the former telescope is missing as is the mount for the latter telescope. The horizontal and vertical circles measure 3 inches diameter.
Object contributed by National Museum of American History, Smithsonian Institution