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. |
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 |
Calendar | Days of year | days | Circular, concentric | Circular scale second in from the outer scale - refers to the full circle. |
Sine/Cosine | 1/60 of quadrant radius | Not numbered | Angle | Upper left quadrant (inside circular scales) |
Unequal hours | 1 - 6, 1/12 of daylight | Every 1 hours | Arc | Upper right quadrant (inside circular scales) |
Shadow square | 1 - 12, Fingers | Every 3 fingers | Box | Left hand vertical 'face' of the shadow square (in LL) |
Shadow square | 1 - 12, Fingers | Every 3 fingers | Box | Right hand vertical face of the shadow square (in LR) |
Shadow square | 1 - 12, Fingers | Every 3 fingers | Box | Left hand bottom face of the shadow square (in LL) |
Shadow square | 1 - 12, Fingers | Every 3 fingers | Box | Right hand bottom face of the shadow square (in LR) |
Transcription | Translation | Notes | Type |
---|---|---|---|
الحمد لله حبّس الرئيس الجليل الماجد الحفيل الفقيه الأجل سيدي محمد بن المرحوم بكرم الله تعالى القائم على ما ينبغي (؟) هذا الأصطرلاب على منار مولانا إدريس نفع الله به الذي بالحضرة الفاسية | Praise be to God. My master, the great, glorious, eager ruler, the greatest jurist, Muḥammad, son of the deceased, may God the Exalted have mercy with him, He, who establishes what is right (?), gave this astrolabe as a bequest to the minaret of our master Idrīs, may God make use of him (for the benefit of others), which is in Fez. | Inscription within hour-line diagram | Donation |