Excerpt from Collection and Preservation of Insects and Other Material for Use in the Study of Agriculture
A large number of soil surveys have been made in the United States, and many of the schools are in areas where soil maps are available. The first thing to study is the scale - what the scale is, and what it means. The scale is given at the bottom of the map. Usually 1 inch represents a mile. Let the students measure the dis tance between two roads or between a house and the road about a mile away, or a bend in the road, measuring it on the map in inches and in the field in feet. Give them the number of feet to the mile, and let them check up the distance on the map and on the field.
The next thing is direction. Soil maps always are drawn so that the upper edge is toward the north, and everything is drawn from this position. If there is a compass in the schoolhouse, put it on the map and turn the map until its edge is exactly in the direction of the compass needle. Make all observations with the map in this position. If there is no compass, select a distinct object on the map, such as a crossroads, church, or house, and place the map so that the direction from the school to the object on the map is in line with the same direction in the field. In making observations on the map always hold it in this position. Measure the distance along the line from the schoolhouse to a point in the road. Carry the map to that point, fix it in the original position, and see if the turn ln the road corresponds to the way it is drawn on the map. This gives an idea both of distance and of direction as platted on the map to represent actual conditions in the field.
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