To orient a plane table at a point roughly south of the mid-point of two inaccessible conical hill stations and in the plains, a point is selected in line with AB and table is oriented at by bringing ab in line with AB. A ray is then drawn towards and at the table is oriented by back ray method. The orientation so obtained, is

Surveying and leveling is a measurement process that determines the height of the level and the distance of an area with another elevated surface.

The principle of levelling is to obtain a horizontal line of sight at which the vertical distance of a point above or below this line of sight is found.

The main purpose of balancing in the survey is: Find the heights of the given points in relation to the given data.