1951 Wild N2

The 1951 Wild Heerbrugg N2.
Figure 1: The 1951 Wild Heerbrugg N2.
This Wild Heerbrugg N2 level was part of a large donation to my collection together with a 1962 Wild T2, a 1969 Wild T2E theodolite, a 1960s Jenoptik Koni 007 level, a 1960s Zeiss Opton Ni 2 level, a 1956 geodetic sextant, a 20th c. Askania Tu400, and various accessories.

Provenance
The above mentioned group of instruments once was part of the set of instruments used by the field organisation TGTW of the Survey Department (Meetkundige Dienst, 'MD' in short) of Rijkswaterstaat (part of the Dutch Ministry of Infrastructure and the Environment, responsible for the design, construction, management and maintenance of the main infrastructure facilities in the Netherlands).

It was once sold to them by Ahrend, the main reseller of geodetic instruments here in the Netherlands.

Development
The Wild N2 developed from Wild Heerbrugg's very first instruments, the Wild NII and Wild NKII levels. The differences between the initial NII and the current model are small. The telescope was extended with a fixed sun shade, while the coincidence vial now is fully encapsulated and read through a microscope (see figure 3). In 1969 the instrument was completely redesigned as can be seen from the 1971 version of the instrument in the collection.

The 1951 Wild Heerbrugg N2 from the other side.
Figure 2: The 1951 Wild Heerbrugg N2 from the other side.
Accuracy
Compared to the 1926 Wild NKII little has changed. The telescope has grown to 193 millimetres to facilitate a small sun shade. Its magnification power is specified as "24 or 28 times" (not sure how to interpret this and how much this is for the model shown here). The view is still inverted and has two stadia hairs with a multiplication constant of 100 along the vertical cross-hair (see figure 13).

The coincidence vial (see figure 14) has an accuracy of 30" per 2 millimetres run, which is less than the 20" of the 1926 Wild NKII. Levelling the line of sight should be possible with an accuracy of approximately 0.5".1 Levelling a kilometre double run should be possible with an accuracy of 2.0 millimetres.1

The instrument
Judging from its looks this N2 has had quite a working life. It came complete with its original container and, despite its looks, still is in full working order.

Notes

[1]: See the Wild Levels for every levelling task at the Virtual Archive of Wild Heerbrugg.

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

The Wild N2 compared to its predecessor Wild NKII.
Figure 3: The Wild N2 compared to its predecessor Wild NKII.
 
The serial number 39219 indicates it was made around 1951.
Figure 4: The serial number 39219 indicates it was made around 1951.

The Wild N2 is a reversion level, this is the normal locked setting.
Figure 5: The Wild N2 is a reversion level, this is the normal locked setting.
 
The Wild N2 is a reversion level, the lock is disengaged.
Figure 6: The Wild N2 is a reversion level, the lock is disengaged.

The push-button locking mechanism of the telescope.
Figure 7: The push-button locking mechanism of the telescope.
 
The horizontal clamp and drive screw of the Wild N2.
Figure 8: The horizontal clamp and drive screw of the Wild N2.

Coarse aiming is done with a peep sight and bead.
Figure 9: Coarse aiming is done with a peep sight and bead.
 
The circular vial of the N2.
Figure 10: The circular vial of the N2.

The container of the Wild N2 with inventory number W.A.D. and Ahrend label.
Figure 11: The container of the Wild N2 with inventory number W.A.D. and Ahrend label.
 
The label of the container reads "Fine instrument, be careful!".
Figure 12: The label of the container reads "Fine instrument, be careful!".

The inverted view through the telescope of the Wild N2.
Figure 13: The inverted view through the telescope of the Wild N2.
 
A view through the microscope of the coincidence vial.
Figure 14: A view through the microscope of the coincidence vial.

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