This is the only known sea quadrant made by George Adams in 1751. The piece is hand-signed, dated, and serial numbered by Adams himself. The piece was purchased in 1774 by Francois Boyer, a professor of navigation and and mathematics at the French Royal Navy School in Lorient. The sea quadrant stayed with the Boyer family until it went up for auction in 2014. The piece is in beautiful condition and looks like it was barely used, if ever. It is in the collection at The Mariners' Museum, Newport News, VA.