A transit is setup over a point M on the ground with the transverse axis of the transit 4.9 ft. above that point.
A leveling rod is held vertically on another point N. When a sight is taken on the rod, the telescope is inclined so that the horizontal cross line of the transit intersects the rod at a reading of 4.9 ft.
The observed reading on the vertical limb of the transit is +10° 13’, but is found that there is an index error of +3’.
If the inclined straight-line distance from point M to point N is 154.82 ft. and the elevation of point M is 118.5 ft. What is the elevation of point N ?