Astrolabe Catalogue

 

Small image of astrolabe back with rules or alidades removed. Click to enlarge.
Date ca. 1570
Maker Allāh-Dād
Place Lahore
Material Brass
Inventory no. 47376
Acquisition Presented by J. A. Billmeir in 1957

Back


CHECK the astrological scales on the back of this instrument. I have in the past figured them out..

The back contains 11 scales of the following types:
Type
(click to view scale details)
Range & Units Numbered Geometry Location
Altitude 0 - 90, Degrees of arc Every 5 degrees Circular, concentric Upper right quadrant of outer circular on back of instrument.
Altitude 0 - 90, Degrees of arc Every 5 degrees Circular, concentric Upper left quadrant of outer circular on back of instrument.
Sine/Cosine 1/60 of quadrant radius Not numbered  Angle Upper left quadrant (inside circular scales)
Declination Summer solstice - Winter solstice, Zodiacal divisions, equal or unequal At each sign  Arc Upper right quadrant (inside circular scales)
Cotangent 0 - 50, Fingers Every 5 fingers Circular, concentric Lower left quadrant of outer circular on back of instrument.
Cotangent 0 - 45, Feet Every 5 feet Circular, concentric Lower right quadrant of outer circular on back of instrument.
Shadow square 0 - 12, Fingers Every 1 fingers Box Left hand vertical 'face' of the shadow square (in LL)
Shadow square 0 - 12, Fingers Every 1 fingers Box Left hand bottom face of the shadow square (in LL)
Shadow square 0 - 7, Feet Every 1 feet Box Right hand bottom face of the shadow square (in LR)
Shadow square 0 - 7, Feet Every 1 feet Box Right hand vertical face of the shadow square (in LR)
Faces Astrological face   Inner Box Box 'inside' the shadow square. Common site for triplicities, etc.
Triplicities Zodiacal divisions, equal or unequal   Inner Box Box 'inside' the shadow square. Common site for triplicities, etc.
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