The back contains 19 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. |
Cotangent | 0 - 70, Fingers | Every 5 fingers | Circular, concentric | Lower left quadrant of outer circular on back of instrument. |
Cotangent | 0 - 60, Feet | Every 5 feet | Angle | Lower right 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 |
Lunar Mansions | 0° Aries - 30° Pisces, Lunar mansion | Not numbered | Circular, concentric | Circular scale second in from the outer scale - refers to the full circle. |
Calendar | 0 - 365, Days of year | Every 5 days | Circular, eccentric | Circular scale third in from the outer scale - refers to the full circle. |
Altitude | 0 - 90, Degrees of arc | Every 5 degrees | Circular, concentric | Upper left quadrant (inside circular scales) |
Altitude | 0 - 90, Degrees of arc | Every 5 degrees | Circular, concentric | Upper right quadrant (inside circular scales) |
Sine/Cosine | 1/60 of quadrant radius | Not numbered | Angle | Upper left quadrant (inside circular scales) |
Ecliptic | Summer solstice - Winter solstice, Zodiacal divisions, equal or unequal | Every 6 | Arc | Upper right quadrant (inside circular scales) |
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 vertical face of the shadow square (in LR) |
Zodiacal signs | Aries - Pisces, Zodiacal sign | Not numbered | Inner Circular, concentric | half circle inside the outer 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 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, Astrological face | At each face | Inner Circular, concentric | half circle inside the VI circle (on mashriqi astrolabes) - covering LL and LR |
Triplicities | Zodiacal divisions, equal or unequal | Inner Box | Box 'inside' the shadow square. Common site for triplicities, etc. | |
Altitude of noon sun | None | Not numbered | Arc | Upper right quadrant (inside circular scales) |