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19IO 1 1

1910 II

■|2 '13 1910 "1! 12 '13

Cylinder Bore

Valve Arrangement

Ignition Systems

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 the^re are only a few points available for each curve

A FEW CAUTIONS

for a curve are available, it can be seen that even if there were only three points instead of four in Fig. 242, the curve would still be valuable to convey the desired information. In Fig. 53 and Fig. 54 methods are shown by which charts which are essentially curve charts may be drawn even though there are available only two points for each curve.

Shoriuge

'Surplus

Shorfage 1908

Surplus

Box Can

All Can.

100,000 ZOO,000

Shorfage 1910

Surplus

Bon Can

All Can

Shorloffe 1911

Surplus

loo.ooc zooooo

American Railway Association

Fig. 243. Freight-Car Shortage and Surplus in the United States for Four Years,

1907 to 191 1, Inclusive

The horizontal bars here are so numerous and are placed so close together that the charts have practically the general form of curves drawn vertically instead of horizontally. It would seem just as well to represent the data by real curves drawn with the standard horizontal arrangement

When curves become as widely understood as the bar method of presentation, it will be found that curves can be used advantageously in almost every case where it is now common to use either vertical or horizontal bars.