Astrolabe Catalogue

 

Front of astrolabe without rete or plates. Click to enlarge
Date 13th century
Place North Africa
Material Brass
Inventory no. 41122
Acquisition Bequeathed by T. G. Barnett in 1935

Throne

The throne is of the five-lobed type . The throne is attached with a integrated base. The throne is simple and undecorated.

Ring

The ring is of the simple, squared cross-section type (i.e. a simple ring made from a round rod or piece of metal).

Shackle

Shackle of the omega type (i.e. Ω-shaped shackle). The tabs on this shackle are carved to resemble the head of some sort of animal.

Mater

The mater and limb are of two pieces, riveted construction. There is a notch at the throne that accepts the tabs from the tympans and keeps them from rotating. Scales on the limb:
Type Range & Units Numbered Geometry Location
Degree 0 - 360 Degrees Every 5 degrees Circular, concentric None

The limb is inscribed:
Content Translation Notes Type
[Along edge of limb] The edge of the limb is divided into 91 approximately equal divisions, each marked with some characters. The use of this scale or these inscriptions is not immediately obvious Miscellaneous

Womb


The womb contains the scales normally found on the back of an astrolabe.
The womb contains 6 scales of the following types:
Type Range & Units Numbered Geometry Location
Declination 0 - 90 Degrees Every 5 degrees Circular, concentric Upper right quadrant of outer circular on back of instrument.
Declination 0 - 90 Degrees Every 5 degrees Circular, concentric Upper left quadrant of outer circular on back of instrument.
Zodiacal signs 0 - 30 Zodiacal divisions, equal or unequal Every 5  Circular, concentric Circular scale immediately inside the outer scale - refers to the full circle
Calendar first day of month - last day of month Days of year Every 5 days and end of the month days Circular, concentric Circular scale second in from the outer scale - refers to the full circle.
Lunar Mansions 9° Aries - 8° Aries Lunar mansion Not numbered  Circular, concentric Circular scale third in from the outer scale - refers to the full circle.
Shadow square 0 - 12 Fingers Every 3 fingers Box Left hand vertical 'face' of the shadow square (in LL)
Shadow square 0 - 12 Fingers Every 3 fingers Box Right hand vertical face of the shadow square (in LR)
Shadow square 0 - 12 Fingers Every 3 fingers Box Left hand bottom face of the shadow square (in LL)
Shadow square 0 - 12 Fingers Every 3 fingers Box Right hand bottom face of the shadow square (in LR)
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