The back contains 6 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. |
| 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 | first day of month - last day of month, Days of year | Every 5 days and end of the month days | Circular, concentric | Circular scale second in from the outer scale - refers to the full circle. |
| Unequal hours | Times of day | Not numbered hours | Arc | Upper left quadrant (inside circular scales) |
| Shadow square | 1 - 4, Feet | Every 1 feet | Box | Left hand vertical 'face' of the shadow square (in LL) |
| Shadow square | 1 - 4, Feet | Every 1 feet | Box | Right hand vertical face of the shadow square (in LR) |
| Shadow square | 1 - 4, Feet | Every 1 feet | Box | Left hand bottom face of the shadow square (in LL) |
| Shadow square | 1 - 4, Feet | Every 1 feet | Box | Right hand bottom face of the shadow square (in LR) |