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Surveying involves the measurement of lot of readings. Local attraction is one of the important concept of surveying. Bearings of lines are measured and they depends on magnetic meridian which gets affected by magnetic forces at site. So, calculations need to be done separately to rectify the readings of bearings. Without a further delay, let's how all these calculations can be done properly so as obtained correct readings of bearings of line. What is Local Attraction? A magnetic meridian at a place is established by a magnetic needle which is uninfluenced by other attracting forces. Some of the sources of this effect are: magnetite in the ground, wire carrying electric current, steel structures, railroad rails, underground iron pipes, keys, steel-bowed spectacles, metal buttons, axes, chains, steel tapes etc.​ The local attraction at a particular place can be detected by observing the fore and back bearings of each line and finding its difference.​ If Differen...