National Geographic : 1946 Jul
The National Geographic Magazine Student Guards Learn to Operate a Firefinder On its surface is a circular map of the area, with the lookout station in the center. The rim is calibrated in degrees of the azimuth circle. Spotting smoke, the guard revolves the ring and adjusts the sights until the base of the smoke appears in the cross hairs of the front sight (at elbow). A tape spanning the map measures distances. Fire data are telephoned to the dispatcher a few minutes after spotting. The person on duty in a lookout station is considered "the eye of the entire fire-fighting organization" of his area. He is expected to discover a fire as soon as possible after it originates, to locate it accurately and quickly, to record the data concerning it, and to re port these data by telephone to the office of the ranger station. The lookout, therefore, is directed to have his area under general observation all the day light hours during possibly dangerous fire weather. By so doing he can detect a fire when it is small. He is also directed to give his area a "check look" every twenty or thirty minutes; by a check look is meant an intensive scrutiny of the observed area, one small sector at a time. Usually the schedules for check looks on ad jacent stations are so arranged that a given sector is under scrutiny most of the daylight hours. When a lookout detects a smoke, he locates it by means of a firefinder. How Fires Are Located This instrument has a circular map of a given area screwed to a steel frame. The whole equipment rides on a pair, or two pairs, of tracks fastened to a rigid stand tall enough to clear the windows enclosing the station. The steel rim around the map is engraved to show the 360 degrees of the circle-the azimuth circle. On a movable steel ring be tween the map and the azimuth circle are screwed, opposite each other, perpendicular pieces known as the front sight and the rear sight. The front sight is equipped with a vertical hair and two horizontal hairs, to be used in determining the horizontal angle and the vertical angle of a given spot. Across the map, between the front sight and the rear sight, runs a measuring tape, by which the lookout determines distances. At the center of my map is my particular lookout station. The map shows the topography and names the principal landmarks (peaks, rivers, creeks, Forest Service stations) in a radius of twenty miles from my station. It is also a section map, and therefore shows the townships, ranges, and sections of the area covered. When, therefore, I see a smoke, I revolve the sight-bearing ring and I adjust the front sight until, as I look through the peephole of the rear sight, the point of intersection of two hairs in the front sight appears to cut through the center of the base of the smoke.