Contents

• History of the astrolabe
• Resources for constructing an astrolabe
• Description of the astrolabe
• Examples of calculations using the astrolabe
• Glossary of Astrolabe Terms

Introduction

The astrolabe is a remarkable Medieval instrument designed to facilitate astronomical calculations. In that sense it is an analog computer, one that can solve a wide range of problems in trigonometry, Greek solar theory, astrology and problems involving time. It was probably developed in early Roman times and became extremely popular by the fourteenth century. I would hope that those who take the time to explore these pages will appreciate the ingenuity and mathematical skill involved in constructing such a complex and useful instrument.

During these past two years I have used the astrolabe as a laboratory exercise for my students of Astronomy 100 at the University of Wisconsin-Stevens Point. Recently I finished a program that will draw a printable version of a common "classical" astrolabe. The program is included here along with a series of instructions that should allow anyone to learn to details of how this instrument was actually used in practice.