Astrolabe Catalogue

astrolabe, inventory number 35592 from Nuremberg, ca. 1686
Dateca. 1686
MakerJohann Leonhardt Bommel
MaterialGilt brass
Inventory no.35592
AcquisitionLent by Miss Ellen Willmott in 1924

By the late 17th century the production of astrolabes in Europe had waned substantially. Nevertheless, the astrolabe remained an important icon and was incorporated as decoration into other instruments. In particular, it retained its association with mechanical clocks; and many scaled-down, domestic versions were made of the large architectural astrolabe clocks and astronomical clocks which were widely constructed in continental Europe in the 15th and 16th centuries.

This German astronomical clock is an exceptionally nice example. Here the rete of an astrolabe has been incorporated into one face of the clock. Two primary arms on the face indicate the positions of the sun and the moon. The arm indicating the motion of the sun would also provide the solar time. Both arms would rotate above the ecliptic on the rete, showing their progress through the zodiac. At the centre is a scale that counts the age of the moon and a diagram that indicates the aspect between the sun and the moon.

All sixteen stars on the rete are named and correctly placed. The mechanism inside the clock would turn the entire rete, simulating the motions of the stars. However, they serve little function as there is no stereographic projection behind the rete. It is impossible, then, to tell which stars are above the horizon and which are below. For the same reason, it is impossible to tell which sign is rising or to find the altitude of the sun. In practice, the star pointers on the rete are little more than ornamentation.

View all images for this astrolabe
View detailed provenance for this astrolabe


The mater and limb are of other construction. The limb on this astrolabe is the ring of numbers on the face of the clock. Scales on the limb: equal hours scale. More information


The rete contains 16 stars. The zodiac on the rete is labelled: ♈ , ♉ , ♊ , ♋ , ♌ , ♍ , ♎ , ♏ , ♐ , ♑ , ♒ , ♓.

The rete contains 1 scale of the following type: Ecliptic. More information


MHS Home | Contact Us | ©2006 Museum of the History of Science