"A Treatise the Astrolabe" by Geoffrey Chaucer is the work of an avid amateur astronomer who happened also to be England's greatest medieval poet. A user of the astrolabe can plot the movement of the stars, tell time, and calculate numerous other results. Chaucer translated and revised a standard Latin treatment of the astrolabe. His treatise, which is generally regarded as one of the first technical manuals in English and a model of how technical manuals should be written.

Not since 1872 has a free-standing edition of "A Treatise the Astrolabe" been published. Thanks to the expertise of...