R & A Rost Wien
compass theodolite R & A Rost Wien
record number: 14
instrument type: compass theodolite
manufacturer: R & A Rost Wien
serial number: 2959
weight: 4.42 kg
dimensions (l/w/h): 20/16/30 cm
year of manufacture: 1885

The only compass theodolite in the University of Ljubljana, Faculty of Civil and Geodetic Engineering collection was made around 1885. The instrument has a special base that allows it to be mounted on pin tripods. There are only two foot screws. The closed protected horizontal circle is actually part of the compass. The theodolite does not have a repetition screw, which is common for compass theodolites, as the reading on the horizontal circle is always the magnetic azimuth. The vertical semi-circle has an interrupted division, with defined intervals from 0° to 50° and from 360° to 310°. The reading unit of the vernier is 1'.

The instrument was fully restored in 2016. A wooden base was added.

Characteristics
horizontal circle vertical circle
diameter: protected by glass, 7.5 cm, compass with clamping screw unprotected, open, 7,5 cm
type of division: engraved division engraved division
limb implementation: silvered metal bracket silvered metal bracket
division: sexagesimal/sexadecimal sexagesimal (0°- 50° in 360°- 310°)
unit: 30' 30'
Reading
number of reading points: 1 1
reading device: direct reading vernier
number of units: / 30
graduation unit: 0.5° 1'
repetition: no /
Telescope
diameter of objective: 25 mm
magnification: /
type: Ramsden's retractable eyepiece
cross hairs/reticule: Reichenbach's crosshairs, constant 100