14) What is used as vertical arm in index frame of theodolite instrument?

15) What is used as horizontal arm in vernier frame of theodolite instrument?

16) What is the process of turning the telescope in vertical plane about its axis through 180 Degree?

17) What is the term, if rotating telescope in horizontal plane, about its vertical axis in theodolite?

18) What is the term, while the vertical circle is on the right of the telescope and the target on the telescope is down in theodolite?