Bowditch?s and Transit method involves usage of correction of latitude and departure formulae. Graphical method uses Bowditch?s formula for solving graphically whereas Axis method is used in case of length corrections which are having accurate angles.

There are three methods of observing bearings of lines by fast needle method. They are direct method with transiting, direct method without transiting, back bearing method.

Compass surveying is not recommended for areas where local attraction is suspected due to presence of magnetic substance like steel structures, iron ore de, electric cables conveying currents.

The term balancing is generally applied to operation of applying corrections to latitudes and departures. So that £L = 0 and £D = 0. This applies only when survey forms a closed polygon.

It is better to measure included angles clockwise. It is because of graduations of odolite circle increase in this direction.

Due to precision of angular and linear measurements obtained by Bowditch?s method, it is more commonly used, but Transit method will be able to deliver less affected measurements due to corrections applied. Axis and Graphical methods can be applied whenever rough measurements are necessary.

The departure of line is negative in westward. It is termed as westing.

Natural errors are those which are not in over hands or control to adjust. Variation in declination, magnetic changes in atmosphere due to clouds and Strom?s etc also comes under natural errors in compass surveying.

In transversing by direct observation of angles, angles between lines are directly measured by a odolite. The method is refore accurate in comparison to previous three methods.

A deflection angle is an angle in which a survey line makes with prolongation of preceding line. It may vary from 0° to 180°.