1. The distances which are shown by a scale based on a fractional proportion between the land area and the map area. The scale most used for thickly settled or industrially important parts of the country is one linear mile to one linear inch, the proportion of which is 1:63,360 and the map represents a ground area of 15´ of latitude by 1´ of longitude. The map used for the greater part of the country covers an area of 30´ of latitude by 30´ of longitude with a scale of two miles to the inch or a proportion of 1:125,000. In the desert regions of the far west the map covers more territory hence the proportion is greater, 1:250,000. It covers an area of 1° of latitude by 1° of longitude with a scale of four miles to an inch. 2. On the map will be found brown contour lines which are arbitrary lines passing through points of like altitude, thus each represents but one level, such as the shore line at the sea side, and the map presents all the eccentric meanderings of the latter. Every few feet in elevation above sea level or depression below sea level is represented by a contour line and the contour interval or vertical distance between lines is stated at the bottom of the map. This varies from five feet on comparatively level country to 200 feet in the mountains. Usually on about every fifth line appears the exact elevation of that point above sea level. Contour lines close together indicate sudden rise or fall of ground and when these lines are far apart a more gentle slope. Where they bend abruptly inward they represent a valley. From the contour lines we get the relative height of the hills and depth of valleys, and whether they are concave or convex and thus they give the data of the relief or profile of the land--the mountains, hills and valleys. 3. Aside from presenting to us the distances of a region and the relief data represented by the contours which are printed in brown the topographic map pictures the water (sea, lakes, rivers and streams) printed in blue and the cultural works of man printed in black. The features are all indicated by conventional signs, a key to which usually is printed on the back of the map. In reading a map you first direct the upper edge to the north by the aid of the compass or, if the sun shines, by the aid of a watch. Next you locate the camp in relation to prominent landmarks, trails, roads, streams and contours. Then as you travel you note the configuration of the ground, the general direction, and the landmarks. If the general course of the trail is south and west and you are to detour north of it you will only have to run south to get back to your base line or camp. If your course varies to the east or north it will be necessary to make the same distance west or south to get back to your starting point.