To space columns equoHv dong the titne scale, divide the ovoikibte horizontal spoce mio twice as mony spaces os there ore to be columns. Then center the columns on every other division mark begmnirtg with the First from either end.

GRAPHIC PRESENTATION

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Magazine of Wall Street, January 29, 1938.

SCALE .5

A. National Income of the United States in Billions of Dollars from 1929 Through 1937.

When superimposing a bar chart upon a picture, care should be taken to choose a picture which does not have smokestacks or other such buildings which take on the appearance of a bar. The eye automatically compares heights. Superimposing when done correctly is very effective.

PASSENGER CARS MOTOR TRUCKS

iOO 99

1928 '30 "31 32 '33 '34 '35 '36

Federal Re»erve Agent, New York, "Monthly Review

•29 '30 '31 '32 '33 '34 '35 'S* October 1. 1936.

A. Production of Passenger Cars and Motor Trucks in the United States During the First Eight Months of 1928-1936. The First Eight Months of 1929 Equal One Hundred Per Cent.

1. The time series comparison of index numbers in bar form is here supplemented by

actual figures. Thus anyone consulting it is able to quote figures without computing the various heights.

2. However, the figures placed at the top of each bar add to its visual length, resulting in

a false visual comparison. A better position for the figures would be between the date and the bottom of the bar, or in the form of a data table below the chart.