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) |
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 |