Thomas Hornsby's quadrant. This 32 inch mural quadrant was made for Professor Thomas Hornsby before the Radcliffe Observatory was planned and was subsequently transferred. It was constructed at a cost of £80.00 and installed in a small room in Corpus Christie College where Hornsby used it to determine the latitude of Oxford. Hornsby was elected Savilian Professor of Astronomy in 1763 and the first Radcliffe Observer in 1772.