1965 Wild Heerbrugg NK10

The 1965 Wild Heerbrugg NK10.
Figure 1: The 1965 Wild Heerbrugg NK10.
Together with the 1965 Wild NK01 the instrument shown here is a bit of a stranger amidst the collection. Whereas most of the optical geodetic instruments in the collection either come from the high-end of the spectrum or have been playing an important role in the development of them in general, the NK10 is a small engineer's level for tasks requiring medium accuracy.

Together they were however the first two geodetic instruments in the collection and as it is nice to have the whole 'baseline' of levels from the N0 up to the N3 that Wild Heerbrugg created over the years justifies their presence. In addition to that they are coincidentally the same age as I am.

Development
Just like with the theodolites Heinrich Wild started building levels with model number 2. The first theodolite Wild produced was thus the T2, while the first level he produced was the N2 (or rather NII as Wild used Roman numerals for the levels in the early days).

The Wild NK10 from the other side.
Figure 2: The Wild NK10 from the other side.
From these instruments he first stepped up to even better instruments as the T3 and the N3 before developing instruments with lower accuracy to facilitate a wider market.

Accuracy
Being an engineer's level one can not expect the highest accuracy from it. The telescope has a 20 times magnification with a 100 times stadia constant for the stadia hairs. The horizontal vial has an accuracy of 60" per 2mm run which, thanks to the coincidence method, can be levelled with an accuracy of 1.5". As a result of this a 3 millimetres standard deviation for a kilometre double run can be achieved.

The instrument
When the instrument came complete with its original case but was in a sorry state when it arrived. Luckily enough it came together with another NK10 that provided several parts to restore this one and the 1965 Wild NK01 in the collection. After restoration the instrument has been used in the field for several years before it was replaced by a more modern Wild Heerbrugg N1.

If you have any questions and/or remarks please let me know.

The Wild Heerbrugg NK10 with its original plastic container.
Figure 3: The Wild Heerbrugg NK10 with its original plastic container.
 
The three oculars of the NK10 for the vial, the telescope and the horizontal circle.
Figure 4: The three oculars of the NK10 for the vial, the telescope and the horizontal circle.

The horizontal circle with mirrored inscription "NK10 - 04812 93 - 13 7"
Figure 5: The horizontal circle with mirrored inscription "NK10 - 04812 93 - 13 7"
 
The circular vial of the NK10.
Figure 6: The circular vial of the NK10.

The Wild NK10 and NK01 compared.
Figure 7: The Wild NK10 and NK01 compared.
 
A view at the horizontal circle.
Figure 8: A view at the horizontal circle.

A view at the built in coincidence vial.
Figure 9: A view at the built in coincidence vial.
 
An inverted view through the telescope showing the stadia hairs.
Figure 10: An inverted view through the telescope showing the stadia hairs.

Surveyor's crosses Geodetic Sextants Theodolites Total Stations Levels Standards Tools Firms
20th c. hydrostatic level 19th c. water bottle level 19th c. Secrétan Egault 19th c. Tibaut Lenoir 1928 Carl Zeiss Nivellier I 1924 Carl Zeiss Nivellier II 1926 Wild NKII 1948 Wild N1 1951 Wild N2 1965 Wild NK01 1965 Wild NK10 1961 Wild N3 1970 Wild NK2 1977 Wild N3 1999 Wild NA2-GPM3 20th c. Cowley 1960s Jenoptik Koni 007 1960s Zeiss Opton Ni 2