Brand Freres Graphometer
Brass graphometer made by the Brand Freres in Bruxelles.
Product details: Brand Freres Graphometer | Brand Fréres | Boussole theodolite | Survey | Material: Brass
This is the predecessor to the thedolite and a simpler version of the 'Holland circle'. This is a half circle divided into half degrees with a vernier on both ends of the rotating arm reading to 30". The magnetic compass can be read to degrees directly and about half that indirect. The instrument can be set up on a tripod with a conical staff end (like most instruments from that age). Using the fixed pointer it can be aligned on the first object and the with the rotating pointer a secondary object can be pointed to allowing the angle between the two to be measured. Due to the two verniers the angles can be measured both clockwise and anti-clockwise. The intrument can be used vertically as well to allow the measurement of vertical angles.
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Data sheet
- Year
- 1861 - 1906
- Type of use
- Survey
- Material
- Brass
- graduation
- deg
- measuring range
- 180 (angle)
360 (heading) - accuracy
- 1' (angle)
2 (heading) - fine reading
- vernier (double)
- Size instrument (l x w x h) in m
- 0.10 x 0.20 x 0.17
- weight instrument in kg
- 0.7
- Size case (l x w x h) in m
- 0.11 x 0.22 x 0.12
- weight case & in kg
- 0.4
- country obtained from
- Belgium