Since it is difficult to determine the relative areas of circles, a very clear and concise scale should be given. The two methods above give the measurement of the diameters which would correspond to given area representations.

MAPS WITH CIRCLES AND SECTOR CHARTS

Each diac rapi

American Petroleum Institute, N. Y. C , "Petroleum Facts and Figures," 1937.

A. Gasoline Tax Rates in the United States as of Novennber I, 1937.

SCALE .7

Compare this as a method of presenting gasoline tax information with the method shown in 182A.

IIMiatt. aao aooi pn

Nofs tnd pork \C»iil: ctlvt ' b**/. and vaa/ -SAaap. /ani6«, snd wool

U. S. Department of Agriculture. Bureau of Agricultural Economics.

SCALE .5

B. The Average Cash Income Received fronn Meat Aninnals. Meat, and Wool Sold by Farmers in the United States in the Period from 1929 to 1933.

Two sets of data arc presented on this map. The percentage comparison of the sectors shows the distribution of cash income among the three categories at the lower left. The areas of the circles show the amount of cash income.

GRAPHIC PRESENTATION

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