Revolving wooden quadrant, 1.6 meter in radius. Estimated accuracy
of 32.3 seconds of arc,
based on eight reference stars.
Astronomical sextant, 1.6 meter in radius.
Estimated accuracy of 33.2 seconds of arc.
armillary sphere, 1.6 meter in radius. Built in 1581.
Tycho rapidly gave up on using large versions
of classical armillary sphere, as he found
their accuracy compromised by flexing and bending due to the
great weight of the various components. This lead to the design
of equatorial armillaries.
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 20 December 1997 by paulchar@ucar.edu.