The Castle of Knowledge

The first edition of Robert Recorde's The Castle of Knowledge was printed at London by Reginalde Wolfe in 1556. The work is a treatise on the celestial sphere, written in the form of a dialogue between a master and a scholar. It is an original and exhaustive study intended to modernise Proclus and Sacrobosco. It deals chiefly with Ptolemaic astronomy but also includes some geographical information as understood in Recorde's time. In the preface to the reader he extols the heavens as God's h...