The castle of knowledge
The Castle of Knowledge is a 1556 astronomy treatise by the mathematician Robert Recorde, printed in London by Reginald Wolfe for students of the heavens. Its pictures are small woodcut diagrams of circles, great-circle lines, zodiac bands and sightlines between stars and a horizon, drawn in plain black line on cream paper, offering a designer clear geometric schemes for armillary or dial-like motifs.
