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. |
Perpetual calendar | Days of year | days | Circular, concentric | Circular scale third in from the outer scale - refers to the full circle. |
Shadow square | 0 - 12, Fingers | Every 2 fingers | Box | Left hand vertical 'face' of the shadow square (in LL) |
Shadow square | 0 - 12, Fingers | Every 2 fingers | Box | Right hand vertical face of the shadow square (in LR) |
Shadow square | 0 - 12, Fingers | Every 2 fingers | Box | Left hand bottom face of the shadow square (in LL) |
Shadow square | 0 - 12, Fingers | Every 2 fingers | Box | Right hand bottom face of the shadow square (in LR) |
Cotangent | 15 - 30, Fingers | Every 3 fingers | Circular, concentric | Lower left quadrant of outer circular on back of instrument. |
Cotangent | 15 - 30, Fingers | Every 3 fingers | Circular, concentric | Lower right quadrant of outer circular on back of instrument. |