Rounds Versus Positions

The two methods of rounds and positions for horizontal angular measurements are compared from the adjustment point of view. Measurements of equal precision are considered. In the method of positions, the mean values of the angles of the horizon are found to be the adjusted values of the angles according to the method of least squares. Further, the adjusted values of the angles are of equal precision. In contrast, it is found that the mean closing error for a set of rounds should be distributed equally upon the first and the last angle in the horizon only. The mean values of the other angles of the horizon receive no correction. Moreover, the precision of the adjusted first and last angles in the horizon are found to be equal but higher than the precision of the other angles.