5. All letters and figures on this chart were made by hand, showing the perfection which may be attained by practice in lettering.
6. The curve itself stands out clearly from the co-ordinate lines.
7. Figures at various points along the curve indicate matters which are worthy of special notice. Foot notes are not given here, however, as they are only of highly technical interest.
8. Figures for the values of points on the main curve are given at the top of the chart immediately above each corresponding point on the curve. Values may be read correctly from the upper figures rather than guessed at by estimating them roughly on the left-hand scale.
9. The statement "Revenue Tons per Train Mile" at the upper left-hand corner is purposely printed diagonally so that it may serve as a heading for each of the two columns of figures, one at the left and the other at the top of the chart. The diagonal arrangement gives a neater effect than can be obtained otherwise.
10. Though figures for the dotted curve could be shown at the top of the chart the dotted line is of only minor interest here. It is accordingly best to avoid the two columns of figures at the top in order that the figures for the main curve may stand out more prominently.
