Graphic Methods for Presenting Facts
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Fig. 147. Comparative Proportion of Deaths at Different Ages from Pneumonia per 1,000 Deaths from Pneumonia in the Registration Area of the United States, 1890 and 1900
Comparison of the two years can be made instantly throughout the whole range of ages. Age is the independent variable and, hence, is shown here as the horizontal scale. It would be better if a vertical wavy line or some other signal were used to show the change in the horizontal scale for ages below five years
GRAPHIC METHODS
by the use of bars. Granted that the curve of Fig. 149 might not be understood by all the readers of a newspaper, it is nevertheless much more desirable, even in newspaper work, than the method shown in Fig. 148. Though Fig. 149 might not attract deep interest on the part of a newspaper reader, it would not be likely to be misinterpreted. Fig. 148 might serve to attract attention, but what is the use in attracting attention unless a correct impression is given after attention has been attracted.'*
Frequency curves thus far considered have permitted reading from the vertical scale only the actual number or percentage observed corresponding to any point which may be selected on the horizontal scale. Thus, in Fig. 143 (see page 167) we can read from the vertical scale only the per-