The astrolabe was the most important astronomical calculating device before the invention of digital computers and was the most important astronomical observational device before the invention of the telescope. The first work of science education written in a language that may be called English (middle English, actually) was Geoffrey Chaucer's Treatise on the Astrolabe. Chaucer, who today is known principally for writing the Canterbury tales, wrote the Treatise on the Astrolabe for his ten year old son Lewis in 1387. This is some of what Chaucer had to say about the astrolabe.
Little Lewis my son, I have perceived by certain evidences your ability to learn sciences concerning numbers and proportions. I have also considered your anxious and special request to learn the Treatise of the Astrolabe. Then forasmuch as a philosopher has said, `he wrappeth him in his friend, who accedes to the rightful prayers of his friend,' therefore have I given you an astrolabe for our horizon, constructed for the latitude of Oxford. And with this little treatise, I propose to teach you some conclusions pertaining to the same instrument. I say some conclusions, for three reasons. The first is this: you can be sure that all the conclusions that have been found, or possibly might be found in so noble an instrument as an astrolabe, are not known perfectly to any mortal man in this region, as I suppose.
Come to the planetarium and learn about the wondrous device on which Chaucer heaped such praise.  Astrolabes will be passes out to experiment with during the show.  I will need them back at the end of the show.  If you want to buy an astrolabe our college bookstore sells Janus astrolabes  just like my AS101 students buy.

Power point presentation used on 11-19-2005 show.

If you want to hold in your hand a model of the universe, an astrolabe, which is undoubtedly the best astrolabe made in the last 400 years and a peer to the best ancient instruments, in some ways their superior, contact:

James E. Morrison, Janus
18 Kingsbridge Road
Rehoboth Beach, DE 19971
(302) 226-5086

Janus sells laminated in plastic, cardboard astrolabes for any latitude personalize with any name in at least three different styles: Modern, Junior, and Classical. Besides the astrolabe a 40 plus page booklet is included telling how to use the astrolabe and some of it fascinating history. Every introductory astronomy course should include an astrolabe for the students to use. Of course, first the instructor should learn to use one, too. They are required in my ASTR101, Introductory astronomy course; and the Modern style astrolabe is sold in our college bookstore. Every amateur astronomer should own and know how to use an astrolabe. Anyone interested in the history of science should own and know how to use an astrolabe. Any well educated person should own and know how to use an astrolabe.

During the 19 November 2005 "Astrolabe" show one of the visitors in the audience told me about the Antikythera.   We googled it after the show and found many facinated references.  On Friday, May 28, 2010 I went to "The Antikythera Mechanism" lecture at the GSFC.  More reasearch has been done on this interesting astronomcal calendar computer see .

Montgomery College's Planetarium home page

Web page by Dr. Harold Alden Williams.
Last changed Monday, 1:43P.M. October 26, 2015.