The back contains 9 scales of the following types:
Type (click to view scale details) |
Range & Units | Numbered | Geometry | Location |
---|---|---|---|---|
Degree | 0 - 90, Degrees | Every 10 degrees | Circular, concentric | The entire outer circle on the back of an astrolabe. |
Zodiacal signs | 0 - 30, Zodiacal divisions, equal or unequal | Every 10 | 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 10 days | Circular, concentric | Circular scale second in from the outer scale - refers to the full circle. |
Saints' Days | Days of year | days | Circular, concentric | Circular scale third in from the outer scale - refers to the full circle. |
Unequal hours | 1 - 12, 1/12 of daylight | Every 1 hours | Arc | The upper two quadrants of the back of the instrument |
Shadow square | 1 - 60, None | Every 10 | Box | Left hand vertical 'face' of the shadow square (in LL) |
Shadow square | 1 - 60, None | Every 10 | Box | Right hand vertical face of the shadow square (in LR) |
Shadow square | 1 - 60, None | Every 10 | Box | Left hand bottom face of the shadow square (in LL) |
Shadow square | 1 - 60, None | Every 10 | Box | Right hand bottom face of the shadow square (in LR) |
Planetary hours | 1 - 12, None | Every 1 | Inner Box | None |
Shadow square | 1 - 12, Fingers | Every 3 fingers | Box | All four sides of the shadow square, commonly found in the lower half of the center of the instrument. |
Transcription | Translation | Notes | Type |
---|---|---|---|
Erasmus Habermel fe: | Erasmus Habermel made this | This inscription is found below the ornament underneath the shadow square | Maker's signature |