The Art Of Dialling (1638)

Samuel Foster’s The Art of Dialling is particularly noteworthy for two reasons. First, it contains the first appearance of dialing scales. For over two centuries following Foster, the latitude and hour scales he introduces in this book were recognized as providing the simplest means for laying out hour lines. Although George Serle was probably the first to put the scales on a ruler, he himself clearly attributes their invention to Foster. Second, it includes an interesting approach to drawing a dial on an arbitrary plane: Foster demonstrates how any plane can be treated as though it were the special case of a direct east - west plane, and then he completely solves the special case. This book consists of a facsimile reprint of the 1638 edition of The Art of Dialling. It also includes the full text of the 1675 edition produced by Leybourn and a paragraph by paragraph comparison of the two.