Explanatory notes
… Optical or opto‑electronic theodolites (vernier reading, microscope, suspended (wall‑stand type), universal, mining, … in survey or artillery, etc. (2) Optical levels (spirit, autoset, telescopic, collimator, laser, etc.), generally … (whether or not with a telescope), optical squares and cross‑staffs (whether or not with prisms) and pantometers …