Astrolabe Catalogue

 

Small image of astrolabe back with rules or alidades removed. Click to enlarge.
Date 1521
Place Germany
Material Brass
Inventory no. 47657
Acquisition Presented by Lewis Evans in 1924

Back


The upper portion of the back bears a diagram of the celestial spheres, with planetary symbols for each of the planetary spheres. Four blank spheres at the center were perhaps intended for symbols of the four elements.

The back contains 5 scales of the following types:
Type
(click to view scale details)		 Range & Units Numbered Geometry Location
Degree 0 - 90, Degrees Every 10 degrees Circular, concentric The entire outer circle on the back of an astrolabe.
Zodiacal signs 0 - 30, Zodiacal divisions, equal or unequal Every 10  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 10 and end of month days Circular, concentric Circular scale second in from the outer scale - refers to the full circle.
Lunar Mansions Lunar mansion Each one  Circular, concentric Circular scale third in from the outer scale - refers to the full circle.
Shadow square 1 - 12, Fingers Every 3 fingers Box The lower two quadrants of the back of the instrument
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