Astrolabe Catalogue

The back contains 9 scales of the following types:

Type (click to view scale details)	Range & Units	Numbered	Geometry	Location
Altitude	0 - 90, Degrees	Every 5 degrees	Circular, concentric	Upper right quadrant of outer circular on back of instrument.
Altitude	0 - 90, Degrees	Every 5 degrees	Circular, concentric	Upper left quadrant of outer circular on back of instrument.
Lunar position	0 - 180, None	Every 6	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 - 35, Feet	Every 5 feet	Circular, concentric	Lower left quadrant of outer circular on back of instrument.
Cotangent	0 - 50, Fingers	Every 5 fingers	Circular, concentric	Lower right quadrant of outer circular on back of instrument.
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	Every 1 fingers	Box	Right hand bottom face of the shadow square (in LR)
Shadow square	0 - 12, Fingers	Every 1 fingers	Box	Right hand vertical face of the shadow square (in LR)

The back is inscribed:

Transcription	Translation	Notes	Type
صنعه عبد الائمة المحتاج ٳلى رحمة ربه الغني	Made by ʿAbd al-Aʾimmah, who needs the mercy of his Lord, the self-sufficient.	Inscription in cartouche below shadow square	Maker's signature