Astrolabe: Guide to Use of the Astronomical Instrument

What is an Astrolabe ? To answer this question in simple language was Geoffrey Chaucer's (astronomer-poet) chief object. He wrote his "Treatise on the Astrolabe" in 1387 for little Lewis, his lo-years- old son, to learn at Oxford. Manuscript copies of this work of Chaucer approaching completeness are very few in number and inaccessible to the general reader. He undoubtedly obtained the greater part of his book from Latin version of the Compositio et Operatio Astrolabii of Messahalla, an Ara...