Cost _v._ value of service, 166.--Relative merits of each, 167.-- Charging what the traffic will bear, 169.--Unduly high and low rates, 171.--Dynamic force in value of service, 177.--Cost of service in classification, 179.--Wisconsin paper case, 181.--Cost and value of service equally important, checking one another, 184. Not only must rates of all sorts be delicately adjusted to suit the immediate exigencies of trade; they must be constantly modified in order to keep pace with its ever changing conditions. This is peculiarly true of a rapidly growing country like the United States. An admirable instance is afforded by the complaint of the Lincoln Commercial Club before the Interstate Commerce Commission.[119] Lincoln, Nebraska, lies about fifty-five miles southwest of Omaha. Originally all its supplies came from the East, as both cities were for a time outposts of civilization. The coal supply came from Iowa and Illinois, and the salt from Michigan. On these and most other commodities the rates to Lincoln were made up of a through rate from the East to the Missouri river, plus the local rate on to destination. The city of Lincoln thus paid considerably more than Omaha for all of its supplies. Gradually conditions have changed; until in 1907 it appeared that over half the soft coal consumed in Lincoln was brought from Kansas and Missouri; four-fifths of the lumber from the South and nearly all the rest from the Pacific coast; glass and salt from the gas belt and salt beds of Kansas; and a great deal of beet sugar from the western fields. For a large proportion of these and other supplies, Lincoln was actually as near or nearer the point of production than Omaha, and yet the difficulties of effecting an adjustment between rival carriers had prevented any modification of rates corresponding to these changes in economic conditions. On every one of these commodities the rate to Lincoln remained steadily higher than to Omaha, regardless of the source of supply. Unanimous consent was necessary for readjustment. So long as any single road refused assent, a general rate disturbance might be precipitated by any independent action. The beneficent effect of the exercise of governmental authority, powerful enough over all interested parties to compel acquiescence, has been clearly apparent in affording relief.