The Increasing Number of Students in the Co-operative Course of the Engineering College of the University of Cinciruiati

This illustration was originally used as a companion piece to the chart of Fig. 51. For a popular exhibit the use of vertical bars brings out information quite clearly. Though curves (such as are shown in later chapters) are superior to vertical bars, it is imfortunately true that most people do not know how to read even the simplest curves correctly.

Note the lettering at the upper portion of the chart. Lettering of this kind may be had by using separate gummed letters such as may be purchased ready for use

GRAPHIC METHODS

as decreasing 4 per cent. The scale would read upward from the zero line for increases, and downward from the zero line for decreases. By changing the scale and using a broad zero line, misinterpretation of the chart would be entirely prevented.

Fig. 54 is somewhat similar to Fig. 53 in that intervening years are neglected, and that lines drawn from left to right of the chart indicate the total movement rather than short-time fluctuations. Fig. 54 would be better if the lines around the outside of the drawing had been omitted. In general, lines of this kind around the outside of a chart are likely to be confusing. In this case, the double lines at the bottom of the chart draw too much attention to the bottom

and may cause a wrong interpretation of the chart. As charts of this type are usually made so as to have the bottom at zero, the reader of Fig. 54 may get an entirely erroneous idea of the actual increase in the rates of wages. This chart of Fig. 54 should have been drawn with % inch more room at the bottom so that the scale would begin at zero rather than at $1.00.