Bessel Solution

It involve the below described steps:

1.      Keep the bevelled edge of alidade along ba & sight object at A. Clamp the table and draw bc′ along the line bc .(ref fig b)

2.      Keep bevelled edge of alidade along ab, unclamp the table & sight B. Clamp the table.

3.      Draw line ac which is intersecting bc′ at d [ref.Fig. (b)].

4.      Keep the alidade   along dc and bisect C. Clamp the table [Fig. (c)]. This gives the accurate orientation.

5.      Draw resectors to obtain  'p'.

                        (a)                                       (b)                                                 (c)                             (d)

                                           Graphical solution (Bessel's method)