Page:Graphic methods for presenting facts (1914).djvu/264

 case of emergency. One prominent manufacturer of locks for bank vaults uses a map which shows at all times the location of each of some fifty bank-lock experts who are routed from city to city each day by telegraph. The locations of the pins, and the railroad lines represented on the map, show instantly which man can best be sent to any bank which reports trouble regarding the door of its safe-deposit vault. Letters or numbers on the pins indicate the name of each man so that there is no danger of an error such as might occur if the pins were colored uniformly without specific letters or numbers.

Fig. 196. Map to Show the Location of the Selling Branches of a Large Manufacturing Company

This line cut was made directly by photographing a standard map in which standard map pins had been inserted. Black pins with white letters or numbers give excellent advertising copy with absolutely no drafting work required

The argument of Fig. 197 would have been brought out better if the railroad tracks had been drawn in heavy black lines across the city map. Unless one is familiar with the city of Indianapolis, there would be no way of explaining the heavy soot deposits in that section shown on the lower portion of the map. Even the mention of railroad tracks in the title does not make up for not showing them on the chart.

In preparing Fig. 198 a scale was very carefully selected to use one dot to represent a definite number of people so as to avoid having dots crowd each other too closely on the map. A map of this kind could be made in a very large size, and then be reduced photographically to a