The first principle of surveying is to work from whole to part. Before starting actual survey measurements, surveying is to work from around area to fix best positions of survey lines and survey stations.

Before selecting survey stations, surveyor should investigate various difficulties that may arise and think of ir solution and examine Intervisibility of stations.

By using A=A'(L?/L)² and L?/L=(L+?L)/L=1+e where e = ?L/L.

During reconnaissance, a reference sketch of ground should be prepared. A general arrangement of lines, principal features such as buildings, roads etc should be shown.

If it is less than 30° n chance of error increases in triangulation.

A site square designed for setting out straight lines and offset lines at 90 degrees. It can be used in conjunction with a datum rod into base of instrument.

The above symbol is standard conventional sign for boundary marker. This symbol is used to represent boundary marker in topographic map.

The Plumbing fork used in large scale work, is meant for centering table over point or station occupied by plane table when plotted position of that point is already known on sheet.

Extended hand of surveyor implies that assistant should continue to move. Left hand of surveyor implies that assistant has to move left side.

Pedometer is a device similar to passometer except that, adjusted to length of pace of person carrying it. Passometer avoids monotony and strain of counting paces.