English: In this drawing, a base end station in each of two fire control towers measures the angle between the premeasured baseline (shown in yellow) and their line of sight (shown in red) to the target ship (the angles between the yellow line and each of the red ones). Once these angles are communicated to a battery's plotting room, the position of the ship can be determined through triangulation, either on a plotting board or using an electro-mechanical gun data computer. The firing coordinates are then sent to the guns, either by telephone or (in the more modern example) by wire directly to servos controlling the guns.