6. If vertical angles of inclined sights do not exceed 10° and non-verticality of the staff remains within 1°, stadia system of tacheometric observations are made on
Correct Answer: and plotting proceed simultaneously
9. A dumpy level was set up at mid-point between pegs A and B, 80 m apart and the staff readings were 1.32 and 1.56. When the level was set up at a point 10 m from A on BA produced, the staff readings obtained at A and B were 1.11 and 1.39. The correct staff reading from this set up at S should be