The back contains 12 scales of the following types:
| Type (click to view scale details) |
Range & Units | Numbered | Geometry | Location |
|---|---|---|---|---|
| Altitude | 0 - 90, Degrees | Every 5 degrees | Circular, concentric | Upper right quadrant of outer circular on back of instrument. |
| Altitude | 0 - 90, Degrees | Every 5 degrees | Circular, concentric | Upper left quadrant of outer circular on back of instrument. |
| Sine/Cosine | 1/60 of quadrant radius | Not numbered | Angle | Upper right quadrant (inside circular scales) |
| Shadow square | Feet | Not numbered feet | Box | Upper left quadrant (inside circular scales) |
| Shadow square | Fingers | Not numbered fingers | Box | Upper left quadrant (inside circular scales) |
| Unequal hours | 1 - 6, Times of day | Every 1 hours | Arc | Lower left quadrant |
| Unequal hours | 1 - 6, Times of day | Every 1 hours | Arc | Lower right quadrant |
| Calendar | None | Not numbered | Inner Circular, concentric | The lower two quadrants of the back of the instrument |
| Cotangent | 0 - 60, Fingers | Every 5 fingers | Circular, concentric | Lower right quadrant of outer circular on back of instrument. |
| Cotangent | 0 - 55, Fingers | Every 5 fingers | Circular, concentric | Lower right quadrant of outer circular on back of instrument. |
| Cotangent | 0 - 40, Feet | Every 5 feet | Circular, concentric | Lower left quadrant of outer circular on back of instrument. |
| Cotangent | 0 - 28, Feet | Every 5 feet | Circular, concentric | Lower left quadrant of outer circular on back of instrument. |
| Zodiacal signs | Aries - Pisces, Zodiacal sign | Not numbered | Inner Circular, concentric | The lower two quadrants of the back of the instrument |
| Lunar cycle | None | Not numbered | Inner Circular, concentric | The lower two quadrants of the back of the instrument |