Astrolabe Catalogue

 

Small image of astrolabe back with rules or alidades removed. Click to enlarge.
Date 1634/5 (A.H. 1044)
Maker Qā’im Muḥammad ibn ‘Īsa
Place Lahore
Material Brass
Inventory no. 42730
Acquisition Presented by Lewis Evans in 1924

Back



The back contains 19 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.
Cotangent 0 - 70, Fingers Every 5 fingers Circular, concentric Lower left quadrant of outer circular on back of instrument.
Cotangent 0 - 60, Feet Every 5 feet Angle Lower right 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
Lunar Mansions 0° Aries - 30° Pisces, Lunar mansion Not numbered  Circular, concentric Circular scale second in from the outer scale - refers to the full circle.
Calendar 0 - 365, Days of year Every 5 days Circular, eccentric Circular scale third in from the outer scale - refers to the full circle.
Altitude 0 - 90, Degrees of arc Every 5 degrees Circular, concentric Upper left quadrant (inside circular scales)
Altitude 0 - 90, Degrees of arc Every 5 degrees Circular, concentric Upper right quadrant (inside circular scales)
Sine/Cosine 1/60 of quadrant radius Not numbered  Angle Upper left quadrant (inside circular scales)
Ecliptic Summer solstice - Winter solstice, Zodiacal divisions, equal or unequal Every 6  Arc Upper right quadrant (inside circular scales)
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)
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
Terms 0° Aries - 30° Pisces, Zodiacal divisions, equal or unequal At each term  Inner Circular, concentric half circle inside the VI circle (on mashriqi astrolabes) - covering LL and LR
Faces 0° Aries - 30° Pisces, Astrological face At each face  Inner Circular, concentric half circle inside the VI circle (on mashriqi astrolabes) - covering LL and LR
Triplicities Zodiacal divisions, equal or unequal   Inner Box Box 'inside' the shadow square. Common site for triplicities, etc.
Altitude of noon sun None Not numbered  Arc Upper right quadrant (inside circular scales)
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