There are a number of instruments used in the land surveying process and in this article we have thrown light on the history of the one of the most ancient land surveying instrument called as the plumb bob. This is one of the finest instruments and it is used till date to determine a vertical line. This instrument is made based on the observation that if a heavy object is hung on a string it causes the string to hang in a perpendicular direction to the earth. By the year 2600 B.C the Egyptians were aware of this concept and thus they invented these earliest surveying instruments like the plumb board, the A-Level, T-Level and plumb square. The first usage of the instrument was made against a wooden frame wherein it stood in parallel against the surface that was measured. Hence a precise judgement was arrived at the horizontal level. These bobs were actually stones but in the shape of eggs, however it is important to note the fact that the shapes actually did not matter much.