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1.5.1.3 Elimination of Parallax

- Remove the lid from the object glass.

- Hold a sheet of white paper in front of the object glass.
- Move the eyepiece in or out until the cross hairs are distinctly visible.
- Direct the telescope towards the staff.

- Turn the focusing screw until a clear and sharp image in formed in the

plane of the cross hairs.

1.5.2 Elevation between two points

- Let A and F be the two given points whose difference is elevation is to be

found.
- Set the level at a convenient point O1 carryout temporary adjustments

and take B.S on A
- Take FS on the Point C
- Shift the instrument to point O2 and perform temporary adjustments.

- Take B.S on C.
- Take I.S. on D.

- Take F.S on E
- Shift the instrument to point O3 and perform temporary adjustments.
- Take B.S on E

- Take F.S on F.
- Find the difference in elevation between A and B by both the methods.

Result: Difference in elevation between A and F = ……………

5 | Soil Engineering Practical Workbook