Page:Graphic methods for presenting facts (1914).djvu/368

 real reason why Fig. 241 should have the curves arranged in the vertical direction. The vertical arrangement confuses the reader until he ascertains how the curves may be read by turning the book so that the curves may be read from the left in their proper position.

Fig. 242. Comparison of American Automobiles for Four Years, in Cylinder Bore, Valve Arrangement, and Ignition System

The standard arrangement of the curves on this chart permits easy reading. Notice that curves are perfectly feasible as a method of presentation even though there are only a few points available for each curve

Fig. 242 shows the data of Fig. 241 plotted in standard manner. Fig. 242 is also of interest because it shows curves plotted from only a few points for each curve. Though one may be tempted to use some other method than curve presentation when only few points