This consists of a white plastic planisphere with the northern sky on one side and the southern on the other, seven clear plastic templates centered at 10o intervals of latitude, and a cardboard container. The United States Hydrographic Office transferred it to the Smithsonian in 1957.
Ref: G. T. Rude, Star Finder and Identifier," U.S. patent #1,401,446
H. M. Jensen, et. al., "Navigational Instrument," U.S. patent