| record number: | 17 |
| instrument type: | theodolite |
| manufacturer: | Otto Fennel & Söhne Kassel |
| serial number: | 19935 |
| weight: | 4.28 kg |
| dimensions (l/w/h): | 31/15/23 cm |
| year of manufacture: | 1900 |
| centering and leveling the instrument: |
plumb bob
two perpendicular toric levels on the alidade precise reversible levelling toric level on the telescope |
The theodolite was made at the beginning of the 20th century. The telescope has a reversible levelling toric level mounted on it to allow levelling. The instrument's telescope already has internal focusing.
The instrument has an open, unshielded horizontal circle, but the special feature of the theodolite is the shape of the vertical circle. The circle is not a full circle (135°) and the division is interrupted and covers the interval between -65° and 65°. A part of the graduation unit of the two 30' divisions is determined using verniers, which provide the division resolution of 1'. The instrument's telescope is internally focused and the objective diameter is 35 mm.
The instrument was polished and partially lacquered in 2016 and is in excellent condition.
| horizontal circle | vertical circle | |
|---|---|---|
| diameter: | unprotected, 12 cm | unprotected, 12 cm, only a quadrant from -65° do 65° |
| type of division: | engraved division | engraved division |
| limb implementation: | silvered metal bracket | silvered metal bracket |
| division: | sexagesimal/sexadecimal | sexagesimal/sexadecimal |
| unit: | 30' | 30' |
| Reading | ||
| number of reading points: | 1 | 1 |
| reading device: | vernier | vernier |
| number of units: | 30 | 30 |
| graduation unit: | 1' | 1' |
| repetition: | no | / |
| Telescope | ||
| diameter of objective: | 35 mm | |
| type: | telescope with internal focusing | |
| cross hairs/reticule: | Reichenbach's crosshairs, constant 100 | |