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Tuesday, March 23, 2010

Astrolabes: Scientific and Cultural Overview

Recently at MIR Appraisal Services, Inc., our research team has been working on a fascinating and incredibly ornate astrolabe, a complex computation device used by scholars for thousands of years. Composed of a brilliant bronze and intricately decorated with astrological characters on the reverse, the entire piece is covered in Hebrew characters carefully hand-engraved into the surface. Complete with moving parts and an elaborate celestial sphere, the swinging hand used for measurement is held in place with a pointer decorated with a figural bird. The piece is a striking reminder of a time when scientific instruments were crafted by masters of their trade and were created as much for their functional purposes as for their ability to display the wealth and taste of their owners.

Throughout history, astrolabes have been used by astronomers and navigators to locate and anticipate the position of the celestial bodies such as the sun, moon, planets and stars. Beyond this they were used as a means of telling time and surveying vast territories of land. The scientific Swiss Army Knife of their time, the astrolabe is much more delicate than the mariner’s astrolabe which was invented to weather the harsh conditions of the sea. Originally invented by the Greeks one century before the Common Era, astrolabes were dramatically refined and improved by the Medieval Islamic world and often used as a way of finding Mecca for prayer or travel. In the 10th century Al Sufi, arguably the most famous astronomer of the Islamic world, noted that there were over 1,000 uses for the device, proving its vast utility as an instrument of knowledge and navigation (Winterburn).

A typical astrolabe is composed of four main pieces, the mater, rete, plates and alidade. The mater is the brass plate which is often ornately decorated and toped with a ring for hanging. The rete is the top plate which is a curvy net looking perforated plate that shows the fixed stars and the ark of the sun, a beautiful and complex layer placed over the plates beneath. The plates are tailored for different latitudes and can be interchanged to display the appropriate horizontal orientation. Finally, the alidade is a rule that moves and is used for making observations and calculations according to its orientation (Winterburn).

Besides the astrolabe there are other useful and alluring instruments including the armillary sphere, astrarium, astronomical clock, orrery and astronomical sextant. Of slightly various purposes and forms, these instruments are united in their old world craftsmanship and concern with the movement of heavenly bodies. These simple calculators were used by scholars to build the vast knowledge of the earth and stars that modern day scientists are building upon with the aide of more advanced technology including supercomputers, satellites and space shuttles. It must be remembered that these early devices and the minds behind them are the foundation of our knowledge of such distant objects.

A part of any well-rounded gentleman’s cabinet in the 16th through 18th centuries, instruments of this nature were highly prized and valued. The point is driven home by the painting “The Ambassadors” by Hans Holbein the Younger created in the middle of the 16th century. Now held at the National Gallery in London, the painting depicts two worldly men amidst a clutter of objects representing both the heavens and the earth as well as the vast range of knowledge maintained by powerful men and kingdoms. Among the objects depicted are celestial calculators and globes. A century or so later Vermeer would paint “The Astronomer,” a depiction of a scholar carefully considering a celestial globe; seized by the Nazis in 1940, the painting is now in the collection of the Louvre.

Astrolabes and other scientific instruments of the era are incredibly collectible because of the ever-increasing market of those interested in the sciences, the consistent collector market interested in historical objects and the constant group of those who are attracted to items of high quality and beauty. Their value understandably varies according to the age, origin, provenance, material and craftsmanship. Scholarship on such items and those who used them are on the rise in the academic arena of history, with some of the most interesting new books and articles chronicling the use of science in relation to the Islamic and European royal courts.

MIR Appraisal Services, Inc. is a fine art and antiques appraisal company that places a premium on research and client satisfaction. Employing a team of experts knowledgeable in various fine arts objects, MIR’s employees go the extra mile and dig deep into the interesting histories of the pieces brought to their attention by clients. Far from just giving an accurate monetary appraisal MIR offers clients true insight into the deeper value of their treasured items. 

Written and Researched by Justin Bergquist 

MIR Appraisal Services, Inc.
Principal Appraiser: Farhad Radfar, ISA AM
307 N. Michigan Avenue, Suite 308
Chicago, IL 60601
(312) 814-8510

Works Cited:
Winterburn, Emily. “Using an Astrolabe,” on

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    Chicago, Illinois, United States
    Welcome to our blog site! MIR Appraisal Services, Inc. is a fine art and personal property appraisal company dedicated to serving clients throughout the United States and abroad since our incorporation in Chicago in 1994. We specialize in the multi-faceted field of appraising fine art, jewelry, antiques, and decorative items. We also provide professional fine art restoration and conservation treatment for various media, including but not limited to, artworks on canvas, board, masonite, and paper. We offer professional and precise appraisal services carried out by our team of accredited appraisers for the purposes of insurance coverage and claims, charitable donations, estate planning and probate, equitable distribution and fair-market value. We started our art commentary blog site as a venue for colleagues and fellow art enthusiasts to share their experiences within the art community.