Page:Graphic methods for presenting facts (1914).djvu/133

 point were not represented at the left, it would be necessary for the reader to glance several times from the left-hand end of one curve to the right-hand end of the preceding curve to determine in his own mind just what changes had occurred from December to January at the end of each year. The repetition of the point for the last month in each year saves time to the reader and also insures against errors which might otherwise occur in the interpretation of the chart.

Fig. 102. Comparison since 1850 of the Merchant Tonnage of the United Kingdom with that of the United States

Gross tonnage is given for the United States and net tonnage for the United Kingdom. Solid lines United States, dotted lines United Kingdom. The "total" figures are not strictly comparable because of the difference in registration method. The general tendencies of the curves are instructive, however. Note the reduction in the foreign trade of United States since the Civil War and the steadily increasing foreign trade of the United Kingdom

In Fig. 104 three distinct subjects are compared on one chart and, at the same time, the data for each subject are shown for three