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 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.
Unequal hours	1 - 6, 1/12 of daylight	Every 1 hours	Arc	Upper right quadrant (inside circular scales)
Sine/Cosine	1/60 of quadrant radius	Not numbered	Angle	None
Cotangent	0 - 30, Feet	Every 5 feet	Circular, concentric	Lower left quadrant of outer circular on back of instrument.
Cotangent	0 - 40, Fingers	Every 5 fingers	Circular, concentric	Lower right quadrant of outer circular on back of instrument.
Shadow square	1 - 7, Feet	Every 1 feet	Box	Left hand vertical 'face' of the shadow square (in LL)
Shadow square	1 - 7, Feet	Every 1 feet	Box	Left hand bottom face of the shadow square (in LL)
Shadow square	1 - 12, Fingers	Every 1 fingers	Box	Right hand bottom face of the shadow square (in LR)
Shadow square	1 - 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 خليل محمد بن حسن علي الحقير الفقير إلى الله الجليل	Made by the contemptible Khalīl Muḥammad ibn Ḥasan ʿAlī who is in need of God the Sublime.	In a cartouche within the shadow square	Maker's signature