Astrolabe Catalogue

 

Small image of astrolabe back with rules or alidades removed. Click to enlarge.
Date 1678 (A.H. 1089)
Place Turkey
Material Brass
Inventory no. 43559
Acquisition Presented by Lewis Evans in 1924

Back



The back contains 6 scales of the following types:
Type
(click to view scale details)
Range & Units Numbered Geometry Location
Altitude 0 - 90, Degrees of arc Every 10 degrees Circular, concentric Upper right quadrant of outer circular on back of instrument.
Altitude 0 - 90, Degrees of arc Every 10 degrees Circular, concentric Upper left quadrant of outer circular on back of instrument.
Sine/Cosine 1/60 of quadrant radius Not numbered  Angle Upper right quadrant (inside circular scales)
Declination None Not numbered  Arc Upper right quadrant (inside circular scales)
Shadow square 0 - 7, Feet Every 1 feet Box Left hand vertical 'face' of the shadow square (in LL)
Shadow square 0 - 7, Feet Every 1 feet Box Left hand bottom face of the shadow square (in LL)
Shadow square 0 - 12, Fingers Irregularly numbered fingers Box Right hand bottom face of the shadow square (in LR)
Shadow square 0 - 12, Fingers Irregularly numbered fingers Box Right hand vertical face of the shadow square (in LR)
Cotangent None   Circular, concentric Lower left quadrant of outer circular on back of instrument.
Cotangent None   Circular, concentric Lower left quadrant of outer circular on back of instrument.
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