Astrolabe Catalogue

The back contains 7 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)
Equal hours	1 - 7, Times of day	Every 1 hours	Arc	Upper right quadrant (inside circular scales)
Unequal hours	1 - 6, 1/12 of daylight	Every 1 hours	Arc	Lower right quadrant
Shadow square	1 - 12, Fingers	Every 5 and at 12 fingers	Box	Lower left quadrant
Cotangent	0 - 60, Fingers	Every 5 from 15 fingers	Circular, concentric	Lower left quadrant of outer circular on back of instrument.
Degree	0 - 45, Degrees of arc	Every 5 degrees	Circular, concentric	Upper right quadrant of outer circular on back of instrument.
Degree	0 - 45, Degrees of arc	Every 5 degrees	Circular, concentric	Upper left quadrant of outer circular on back of instrument.

The back is inscribed:

Transcription	Translation	Notes	Type
سنه ١١٢٥	Year 1125		Date