A three-dimensional map may be used as an exhibit on a table, or on a wall. The basic map is flat on paper, wall-board, or wood; and the buildings and other symbols are made of paper, cardboard, or other materials in three dimensions, and fastened at the proper spots.
If the background of the map is to be predominantly one color, such as green for grass, cover the foundation with green paper, paint, or cloth. Make waters-brooks, lakes, etc.-of blue paper or cellophane. Make sand and fields of brown paper.
Decorations). Sponges dyed green make good trees; small twigs of evergreens may be used for temporary maps. Small lumps of clay may be used to make trees, frames, cranes, etc., stand up.
Relief maps are more accurate representations of the terrain than flat or three-dimensional maps. Relief maps show contours of the land, with hills and valleys. This is a fine project for a group of campers to make, either for acquainting new campers with the trails and areas on the camp site, or for in-town promotion activities.
To make a relief map, it is necessary to use and understand a topographical map. These maps are made by the U.S. Geological Survey and may be obtained in local stationery stores, or from the Superintendent of Documents in Washington, D.C. Hikers and trippers should be familiar with the topographical map sections for the area around the camp or in the trip country. On these maps the height of land above sea level is indicated by brown lines with numbers on them. Thus by looking at the lines it is possible to tell if the land rises at all, and if the rise is gradual or sharp. By symbols, the maps indicate swamps, geological formations, rivers, roads, some buildings, and so forth.
To help campers understand the lines indicating contour, cut a potato in half and lay it on a paper (Fig. XX-6 a). This will represent a hill. Draw around the base with a pencil (Fig. XX-6 b). Remove potato, and the contour line on the paper looks like the base of the hill at sea level on the map. If the hill were 300' high, and the lines on the map were 100' divisions, this hill would have three different contour lines. Cut the potato into three horizontal slices, the same thickness. Place the second slice in the first drawing and draw around it. Then place the third or smallest slice in the center of the second drawing, and draw around it (Fig. XX-6 c). In making a relief map, layers of cardboard or wood are nailed or glued together in the same way that the potato slices would be put back together to make the "hill."
Work from a topographical map, or an enlargement of a section of one map, planning the total size of the table or base, which should be strong enough not to warp.
Work out the elevations and contours with pieces of wood or cardboard, and cover the whole base with plaster of paris or papier-mache or similar mixture (see below) to make the map more nearly resemble the land. After the map is dry, paint with opaque water colors (poster paints) to simulate the landscape colors (Fig. XX-7).
Buildings, trees, etc., may be added as desired. Be sure to keep them in scale, otherwise the map will be misleading. The buildings and other symbols will probably be very small; they may be modeled from clay or plasticene and painted with the poster paint.
Mounted map. Fig.XX-8.
A legend should be added either on the map, or on an easel nearby.
Papier-mache: shred newsprint paper into small strips. In a bowl or basin put one pint flour paste (see below) with one tablespoon glue. Thin with water to syrupy consistency. Mix newsprint into paste, and squeeze until mass is pulp-like. Spread over the foundation, molding the terrain to look like the original. Place in warm, sunny place to dry.
Flour paste: mix three-fourths cup cold water and one cup flour in double boiler top. Stir and cook, adding one cup hot water gradually. Add a little powdered clove to discourage mildew. When smooth, it is ready to use.
Paste and sawdust: mix three-fourths cup flour with two cups water, and cook to make paste as thick as white sauce. Add sawdust gradually, as much as the mixture will take. Spread over the contours, as above. Let dry in sunny, airy place.
Plaster of paris: see Chapter IV (Ceramics) on Ceramics.
Paper maps become worn and tear easily when folded and unfolded, so hikers and trippers often mount them on linen or muslin.
Paste the map on a piece of cloth, pressing out any bubbles of air and leaving the map pressed between papers under a heavy weight overnight. The backing may then be trimmed, and the map rolled to go in a pack.
If the map is to be folded and carried in the pack, it is best to cut the map in sections. Paste the sections in order, on a piece of cloth, being sure there is a small space left between the edges, for the fold. Press firmly.
Maps to be used for hiking should be sprayed with clear plastic to keep them clean and easy-to-read.