A variant of the arc method of adjusting a triangulation network, in which the length and azimuth of one side of a triangle at every junction between arcs (chains) are assumed correct and carried into a suitable figure at the junction. Directions or angles in arcs between these figures are then calculated, the corrections in the individual chains calculated, and the misclosures passed into the longitudes and latitudes of the initially fixed sides in the junctions by an adjustment of the entire network, using the method of least squares. The method was devised in the Coast and Geodetic Survey, under the direction of William Bowie, for the adjustment of large triangulation-networks.