PROTRACTOR # 4173 sextant , navigation nools
Added: -0.2-.2019

Price: 149 $

Main characteristics of the device
1. Accuracy of counting 1’.
2. A mistake from a dead course and a bend of rulers 3’.
3. The dead corner of the right ruler doesn’t exceed 3 ?.
4. The error of a drum doesn’t exceed 2’.

The instrument is used for coastal navigation using a sextant.
One could measure the two angles between three coastal objects.
After setting the legs of the station pointer to the right angles
(adjustment is done with two verniers) it can be laid on a map showing
the same objects. With the legs running over the objects on the map the 
center of the instrument
will be your position in the map.