Which of the following is not the error aroused from imperfect adjustment of a theodolite?
1
Axis not vertical in an observation, either from imperfect plate level adjustment or settlement of the instrument.
2
Line of altitude bubble not perpendicular to the line of collimation when the verniers of vertical circle read zero.
3
Line of collimation not perpendicular to the horizontal axis.
4
Horizontal axis not perpendicular to the vertical axis.