Wild Heerbrugg T1
Archetype model of the T1 simple theodolite.
Product details: Wild Heerbrugg T1 | Wild Heerbrugg | Optical theodolite | Survey | Material: Brass
This is a T1 from the early days of Wild Heerbrugg. The instrument differs in some ways from the later T1 that is also in my collection. The difference is however smaller than between the early T2 and the later versions that are also in my collection. For the T1 the main differences are the location of the levelling mechanism of the vertical circle (on top for this instrument whereas integrated in the side mount for the later T1. Another difference lies in the clamping of the vertical circle; on top of the mounting pillar vs to the side of it. There are also many smaller changes. This instrument was used by the 'Rijks geologische Dienst' (Geological Survey of the Netherlands) in Limburg.
The instrument must have had a very long working live as it seems to have been refurbished by Ahrend in 1971. During the refurbishment the people at Ahrend also removed the original 'Wed J. Ahrend' plague on the dome and replaced it with a more modern version. Altough the instrument is externally in very good condition, it does show its age internally. After the refurbishment it does not seem to have been used very often as it is still in very good state.
More information / other collections:
T1
Data sheet
- Year
- 1934
- Serialnumber
- 4262
- Type of use
- Survey
- Material
- Brass
- graduation
- deg
- diameter scale in mm
- Hz: ca 70 | V: ca 55
- accuracy
- 0.5'
- fine reading
- scale micrometer
- image direction
- inverted
- Size instrument (l x w x h) in m
- 0.15 x 0.14 x 0.26
- weight instrument in kg
- 3.8
- Size case (Ø x h) in m
- 0.16 x 0.30
0.17 x 0.30 - weight case & in kg
- 1.5
1.5 - country obtained from
- Netherlands
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Archetype model of the T1 simple theodolite.
Product details: Wild Heerbrugg T1 | Wild Heerbrugg | Optical theodolite | Survey | Material: Brass