The back contains 15 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. |
Declination | Summer solstice - Winter solstice, Zodiacal divisions, equal or unequal | Every 6 | Arc | Upper right quadrant (inside circular scales) |
Prayer lines | 27 - 32, Degrees of latitude | At each limit. degrees | 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 - 60, Fingers | Every 5 fingers | Circular, concentric | Lower left quadrant of outer circular on back of instrument. |
Cotangent | 0 - 60, Feet | Every 5 feet | Circular, concentric | Lower right quadrant of outer circular on back of instrument. |
Shadow square | 0 - 12, Fingers | Every 1 fingers | Box | Left hand vertical 'face' of the shadow square (in LL) |
Shadow square | 0 - 12, Fingers | Every 1 fingers | Box | Left hand bottom face of the shadow square (in LL) |
Shadow square | 0 - 7, Feet | Every 1 feet | Box | Right hand bottom face of the shadow square (in LR) |
Shadow square | 0 - 7, Feet | Every 1 feet | Box | Right hand bottom face of the shadow square (in LR) |
Lunar Mansions | 0° Aries - 30° Pisces, Lunar mansion | Inner Circular, concentric | half circle inside the outer circle (on mashriqi astrolabes) - covering LL and LR | |
Zodiacal signs | Zodiacal sign | Not numbered | Inner Circular, concentric | half circle inside the V circle (on mashriqi astrolabes) - covering LL and LR |
Terms | 0° Aries - 30° Pisces, Zodiacal divisions, equal or unequal | At each term | Inner Circular, concentric | half circle inside the VI circle (on mashriqi astrolabes) - covering LL and LR |
Faces | 0° Aries - 30° Pisces, Zodiacal divisions, equal or unequal | At each limit. | Inner Circular, concentric | half circle inside the VI circle (on mashriqi astrolabes) - covering LL and LR |
Triplicities | Zodiacal divisions, equal or unequal | Not numbered | Inner Box | Box 'inside' the shadow square. Common site for triplicities, etc. |
Transcription | Translation | Notes | Type |
---|---|---|---|
صنعت أضعف العباد محمد مقيم ابن عيسى ابن الهداد اسطرلابي همايوني لاهوري | Work of the weakest of servants Qāʾim Muḥammad ibn ʿĪsā ibn Allāhdād (or: Ilāhdād), the imperial (humāyūnī) astrolabist of Lahore. | Along right edge of shadow square | Maker's signature |
فى سنه ١٢٢١ | In the year 1221 | In a different hand | Date |
فى سنه سكندرى ١٩٥٥ غظنه | In the year of Alexander 1955 1955 | The year is written twice, once in modern Arabic numerals and once in abdjad numbers | Date |
فى سنه هجرى ١٠٥٣ غنج | In the Hijri year 1053 1053 | The year is written twice, once in modern Arabic numerals and once in abdjad numbers | Date |