are covered with lattice work lines of various kinds, and a key indicates the meaning of the arrangement as applied to production. the cotton production of the state of Mississippi. The various counties of the state are blocked in solid or CIRCLE CHARTS Circle charts are quite frequently used by common carriers in showing the sources of revenue and the distribution of expense. They can be employed with equal advantage in industries to show the same factors. Suggested methods of employment are indicated in Fig. 51. Diagram A of Fig. 51 indicates the distribution of moneys paid out for transportation among the several agencies employed by an industry. Diagram B indicates the apportionment of tonnage among representative lines serving an industry. On competitive business it is customary to apportion the traffic impartially among the lines unless the service or the rates of one line attract a preponderance of tonnage. To determine the apportionment of labor, the circle chart may also be employed, as illustrated in Diagram C. Here the work of the claim division of an industry has been charted, indicating a preponderance of claims for overcharge as contrasted with those for damage or for total loss. In Diagram D, the expense of operating the department has been charted in a circle graph. The relationship of expense to recovery of claims is frequently indicated by means of circle graphs, as indicated in Fig. 52. The outer circle represents the amount recovered by a certain traffic department, and the inner circle indicates the expense incurred in maintaining the department. Fig. 53 indicates the adaptation of the circle graph to railway operation. This form may be employed in industrial traffic work in lieu of the diagrams shown in Fig. 51. REGIONAL CHARTS In analyzing the contents of tariffs, especially those applying on specific commodities, it frequently becomes necessary to transfer the various rate adjustments con tained therein to a map of the territory covered by the publication. Fig. 54 is reproduced from an exhibit filed in a case involving rates on lumber from points in southeastern |