Astrolabe Catalogue

astrolabe, inventory number 37878 from Spain, ca. 1260
thumbnail for astrolabe (front), inventory number 37878 from Spain, ca. 1260
thumbnail for astrolabe (back), inventory number 37878 from Spain, ca. 1260
thumbnail for astrolabe (rete front), inventory number 37878 from Spain, ca. 1260
Dateca. 1260
Inventory no.37878
AcquisitionPresented by Lewis Evans in 1924

The throne construction on this instrument is unusual. The front and back plates are cut to the outline of the throne. But the middle section is composed of numerous sheets of metal cut to the shape of the throne and sandwiched between the front and back plate pieces.

This possibly unique approach to constructing a throne is further reflected in the unusual construction of the body of the instrument. It is made of three pieces, consisting of a back plate, a front plate or circle (the surface of the limb), and a thicker cast limb sandwiched between the two, the whole being rivetted together.

To add to the structural individuality there are also several later repairs. A replacement segment of the front of the limb has been let in and rivetted in place. And the rete has broken and been repaired by a rivetted bar across the break on the front and some soldering on the back. For details see the additional images for this astrolabe.

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

Throne, Ring and Shackle

The throne is of the three-lobed type made of brass attached with soldered base made of brass and has a simple, round cross-section ring made of brass and rotating pin type shackle made of brass . More information


The mater and limb are of three pieces construction. This limb is cast and sandwiched between a front and back plates. The scales on the front of the limb are in fact on the front plate that has been cut to the width of the underlying cast piece. The three pieces have been riveted together.. Scales on the limb: degree scale; equal hours scale. More information


The back contains 5 scales of the following types: Zodiacal signs; Calendar; Unequal hours; Shadow square. More information

Rete, Pin & Horse

The rete contains 0 stars. The rete is a replacement. The zodiac on the rete is labelled: Aries , Tauvus , Gemini , Cancer , Leo , Virgo , Libra , Scorpius , Sagitarius , Capricornus , Aquarius , Pisces .
The rete is attached using a pin & horse. Simple, broad head on the pin. The horse is likewise simple.. More information


There are 7 plates with latitudes ranging from 38°0' to 58°0' . More information

Rules & Alidades

Type Details
RuleDouble-ended, counter-changed. The rule is not original. Although this rule is certainly a very early addition to the instrument, it was made of a slightly different metal and engraved in a slightly different style. The style reflects the style used when somebody re-engraved some of the tympans and the limb. This suggests that the rule was added at the same time that the tympans were re-engraved..
AlidadeDouble-ended, counter-changed.
More information


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