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 In geography books, and in other places where maps are most commonly seen, contrasted territories are frequently drawn to such different scales that a true idea of their proportions cannot be obtained. The relative proportion can be indicated best when care is taken to have the several areas drawn to the same scale and placed in a good position for comparison.

Fig. 171 is shown here only as an example of the almost unlimited range which the application of graphic methods may have. The average person would never think of charting a football game, yet the graphic method certainly gives the information more concisely than could words alone.

Fig. 172 will be recognized by many readers as similar in general scheme to the weather maps on which lines are drawn through all points having the same temperature or the same barometric pressure. Contour lines to show those points which are at the same height above sea level give another application of the same general method.

Profile drawings similar to Fig. 173 are commonly used by engineers, but are not as well understood as they should be by others. The main feature of the profile chart is the very great difference between the horizontal scale used to mark distance and the vertical scale showing the height of the points represented. The vertical scale of Fig. 173 should have been shown on the chart. The heights stated for different cities give a fair indication of what the vertical scale is and a reader can, if he must, measure on the drawing the height for any city and from that determine to what scale the drawing has been made. As a broad rule, the scale should be indicated in an easily seen position on every chart, if the scale can be of assistance to any one besides the maker of the chart.

World's Work

Fig. 170. The Comparative Size of the Philippines

By drawing the islands to scale and in solid black on a map of the eastern part of the United States, the relative size is clearly brought out

Considerable time and ingenuity may be used in drawing up a