Although labels usually are kept on a horizontal plane, the small size of the sections may make it impossible to follow this method even by the use of arrows.

2. These data might be more clearly shown by a 100% bar chart.

I9I0-I9I4

1924-1929

AV. PRODUCTION

2,614,000,000 BUS.

AV. PRODUCTION

2,610,000,000 BUS.

U. S. Department of Agriculture, Bureau of Agricultural Economic*. SCALE .7

B. Distribution of Corn in the United States for the Two Periods 19 10- 1 9 14 and 1924-1929.

1. This chart presents the best method of dividing the circle and labelling its parts.

2. The chart is marked clockwise in magnitudes with the first line beginning at 12 o'clock.

3. The lettering of the sections is on a horizontal plane so that it is not necessary to turn

the chart to read the labels.

SECTOR CHARTS

American Society of Mechanical Engineers, N. Y. C, "Mechanical Engineering," February, 1921.

SCALE .5

A. Average Annual Net Expenditure of the Federal Governnnent During the Period 1910 to 1919, and for the Same Period Exclusive of War Cost.

1. If you think of this type of chart as two sector charts, one larger than the other with

the smaller on top, it is much easier to understand.

2. It would have been impossible to put the titles of the segments on a horizontal plane

in this sector chart. Care has been taken, however, to make the lettering clear.

American Atiociation of State Highway Official!, 'American Highway*." April. 1938. SCALE .5