Astrolabe Catalogue

 

Small image of complete astrolabe back. Click to enlarge.
Date 1675/6 (A.H. 1086)
Maker Muḥammad Amīn
Place Persia
Material Brass
Inventory no. 35565
Acquisition Presented by J. A. Billmeir in 1957

Back



The back contains 15 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.
Declination Gemini/Cancer - Sagittarius/Capricorn, Zodiacal divisions, equal or unequal Not numbered  Arc Upper right quadrant (inside circular scales)
Azimuth of Qibla Cities   Arc Upper right quadrant (inside circular scales)
Sine/Cosine 1/60 of quadrant radius Not numbered  Angle Upper left quadrant (inside circular scales)
Cotangent 0 - 45, Fingers Every 5 fingers Circular, concentric Lower left quadrant of outer circular on back of instrument.
Cotangent 0 - 25, Feet Every 5 feet Circular, concentric Lower right quadrant of outer circular on back of instrument.
Zodiacal signs Aries - Pisces, Zodiacal sign Not numbered  Inner Circular, concentric half circle inside the outer circle (on mashriqi astrolabes) - covering LL and LR
Terms 0° Aries - 30° Pisces, Zodiacal divisions, equal or unequal At each term  Inner Circular, concentric half circle inside the V circle (on mashriqi astrolabes) - covering LL and LR
Lunar Mansions 0° Aries - 30° Pisces, Lunar mansion Not numbered  Inner Circular, concentric half circle inside the VII circle (on mashriqi astrolabes) - covering LL and LR
Faces 0° Aries - 30° Pisces, Astrological face Not numbered  Inner Circular, concentric half circle inside the VII circle (on mashriqi astrolabes) - covering LL and LR
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 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)
Triplicities Zodiacal divisions, equal or unequal   Inner Box Box 'inside' the shadow square. Common site for triplicities, etc.
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