Revolving steel quadrant, 2 meters in radius. Built in 1588.
Estimated accuracy of 36.3 seconds of arc.
Thoren, V.E. 1973, Journal for the History of Astronomy, 4, 25.
Wesley, W.G. 1978, Journal for the History of Astronomy, 9, 42.
-Written and last revised 8 November 1998 by paulchar@ucar.edu.