Graphic comparisons, wherever possible, should be made in one dimension only. In such a case as this, one-dimension presentation is perfectly

feasible by the use of bars of different lengths. The pupil would find it an almost hopeless task to fit one side of the block for Brazil into one side of the block for the United States and then square the resulting ratio in order to learn that the United States pro-

O 2SO0 $000 7500 JOOOO

I I n I I 1 I I I I I I I I I I I I

T/ie World- -^-

United States ,..._.

India

Es'ypr

China

Asiatic Jfussia. ,

Fig. 20.

The world's production of cotton, in igoj, in millions of pounds.

Dodge's Advanced Geography

The World's Production of Cotton in 1905 in Millions of Pounds

The above illustration together with the title is shown exactly as given in a recent geography book. Charts like this greatly assist the pupil in getting the correct relative importance of the different things studied. Note the scale duceS rOU^hlv thirtv times at the top of the chart ' & J ' J

as much cotton as Brazil. Bars in one dimension only would show the comparison accuratelv. Under any circumstances, the use of the squares of Fig. 19 with the center line through the centers of the squares gives an extremely poor arrangement.

SIMPLE COMPARISONS

VAtira OF PBODtTCTS FOB PBINCIPAL CITIES: 1909.

CITIES

NEW YORK

CHICAGO

PHILADELPHIA

ST. LOUIS

CLEVELAND

DETROIT

PITTSBURG

BOSTON

BUFFALO