George Trimble & Sapere Aude Books release only English language 

book in print covering modern astrolabe manufacture

Valuable resource for astronomy enthusiasts everywhere


By George Trimble

May 25, 2018


Cleveland, OH— The Theory, Design, Manufacture & Use of The Astrolabe; Wheel of Esoteric, Ancient Wisdom has just been released by Sapere Aude Books and the author, Dr. George Trimble. Five years of research and preparation went into its creation. The book’s release is timed to coincide with the launch of the website supporting its release.


About the astrolabe


            The astrolabe is an ancient astronomical observational tool and analog computer based on the stereographic projection. First conceived by Hipparchus, perfected by Ptolemy and later embellished by the Arabs of antiquity, the astrolabe is used to solve problems relating to the timing and location of astronomical phenomenon. 


            “It can actually tell time, and solve problems in plane and spherical trigonometry,” says Dr. Trimble. 


About the Book


            The release of this book is important, as it represents the only English language resource on the topic in print.


            “There have been other books about astrolabes available in modern times, but none is now in print,” says the author. “None of these previously available books on the subject of astrolabes addressed the very practical question of how to actually manufacture your own working metal device at home using modern tools and techniques.”


            This four–part textbook begins by teaching the ancient astronomy upon which the device is founded. Readers are introduced to the first, second and third motions of the sun; ancient methods of equinox and solstice determination; how to determine the length of the year; the solar anomaly and the surprising variation in the length of seasons. From these observationally determined parameters, Hipparchus reached the startling conclusion that the Earth’s position within the circle of the sun’s motion must be eccentric. “An accurate value for the eccentricity of Earth’s orbit may be derived from the astrolabe drawing by forming the ratio between the lengths of two lines. It is amazing that orbital parameters just jump out of the 2000-year-old drafting methods,” Says Trimble. He goes on to describe how to calculate precession of the equinoxes using mathematics within easy reach of anyone possessed of high school algebra.


            Part two of the book focuses on the geometric construction methods of Ptolemy using inexpensive, modern CAD drawing software. “I wanted the astrolabe to be available to the average guy with a bit of motivation, and drawing software commonly available for $40.00 or less at his local software store or online,” says Trimble. The reader is guided through drawing his own latitude specific device using the geometry of the ancients, avoiding the algebra of previous modern books on the subject which were directed at those interested in writing computer code to programmatically generate the lines of an astrolabe. “There is so much more to be learned about astronomy from doing the drawings like the ancients,” says the author.


            Part three of the book has no equivalent in all of historical writing. It takes the reader step–by–step through the process of safely acid etching a device at home in the kitchen using a method the author perfected for the task. “Without expensive engraving tools and the training to laboriously hand cut the many lines of the astrolabe into a metal plate, the astrolabe would be out of reach to the average maker. My technique makes a working metal astrolabe attainable by anyone,” says Dr. Trimble.


            Naturally, part four of the book is dedicated to the use of the device. “Not since Geoffrey Chaucer wrote A treatise on the Astrolabe has such a detailed treatment on the subject been available in English.”


            Says Trimble “The amateur astronomy enthusiast will love my book. They will harken back to the heady days when they made their first telescope by hand grinding their own optics. I think they will greatly value a new homemade instrument of such observational and predictive power.” He continues: “Anyone interested in the history of science and technology will be appreciative of the detailed historical treatment of how we know what we know.”


            Dr. Trimble is Vice President of The Chagrin Valley Astronomical Society in Ohio and is Editor of The Valley Skywatcher. He is also the Founder of The Eastlake School of Amateur Astronomy. He is the author of Einstein’s Theory of Special Relativity, A Mathematical Approach for Non-Physicists. He is available to lecture to interested groups on either of these topics nationwide. The book is now available for purchase at, where more information is available. It will soon be available at bookstores nationwide.


            For more information or to inquire about lectures for your club or group contact:

 George Layton Trimble IV, MD

36480 Sandy Knoll Dr.

Eastlake, OH 44095