Located either parallel to or pivoting alongside the main telescope eyepiece. It displays both the horizontal and vertical scale circles.
Always lock the horizontal and vertical clamps lightly when placing the instrument back into its fitted transit box to protect the internal axes from jarring impacts. hilger watts theodolite manual
Depending on the model year, the instrument will feature either a optical plummet built into the alidade/tribrach or require a traditional mechanical plumb bob. Located either parallel to or pivoting alongside the