Mechanical Method

This method is known as tracing paper method as it requires a tracing paper. The following step is involved in method as shown in figure.

1. Set the table over station P and approximately orient the table by observation.
2. On the plane table Fix the tracing paper and approximately select P, say as p′. From p′, draw p′ A, p′ B and p′ C. These lines may not pass through the plotted positions a, b and c since the orientation is not precise.
3. Loosen the tracing paper and rotate it so that the rays pass through respective points a, b and c. prick the point now p′ to get the plotted position 'p' of the station P.
4. Keep the alidade along pa and sight A. Then clamp the table. This is right orientation. Verify the orientation by observing along pb and pc.