Page:Graphic methods for presenting facts (1914).djvu/366

 in trying to get a condensed visualization of the chart. There are relatively few curve charts which cannot be presented for report purposes on paper 8-1/2 by 11 inches, the commonest size used for a typewriter. Though the placing of a chart on paper of typewriter size requires more care than is necessary if a very large sheet of paper is used, the resulting chart is frequently more easy to interpret than it would be if made to a larger scale.

Courtesy of "Motor"

Fig. 240. International Road Signs that Are Being Erected on the Highways of Japan by the Nippon Automobile Club

Any conventional symbols or signals adopted for use in graphic work should be as clear and suggestive as it is possible to make them. The above illustration is shown here as an admirable example of good practice in the making of graphic symbols

A warning seems justifiable that the background of a chart should not be made any more prominent than actually necessary. Many charts have such heavy co-ordinate ruling and such relatively narrow lines for curves or other data that the real facts the chart is intended to portray do not stand out clearly from the background. No more co-ordinate lines should be used than are absolutely necessary to guide the eye of the reader and to permit an easy reading of the curves. Too