cient ground for compelling the carrier to transport it for less than cost or without substantial reward. The State insists that the enactment of the statute may be justified as 'a declaration of public policy.' In substance, the argument is that the rate was imposed to aid in the development of a local industry and thus to confer a benefit upon the people of the State. The importance to the community of its deposits of lignite coal, the infancy of the industry, and the advantages to be gained by increasing the consumption of this coal and making the community less dependent upon fuel supplies imported into the State, are emphasized. But, while local interests serve as a motive for enforcing reasonable rates, it would be a very different matter to say that the State may compel the carrier to maintain a rate upon a particular commodity that is less than reasonable, or as might equally well be asserted to carry gratuitously, in order to build up a local enterprise. That would be to go outside the carrier's undertaking, and outside the field of reasonable supervision of the conduct of its business, and would be equivalent to an appropriation of the property to public uses upon terms to which the carrier had in no way agreed. It does not aid the argument to urge that the State may permit the carrier to make good its loss by charges for other transportation. If other rates are exorbitant, they may be reduced. Certainly, it could not be said that the carrier may be required to charge excessive rates to some in order that others might be served at a rate unreasonably low. That would be but arbitrary action. We cannot reach the conclusion that the rate in question is to be supported upon the ground of public policy if, upon the facts found, it should be deemed to be less than reasonable. The legislature, undoubtedly, has a wide range of discretion in the exercise of the power to prescribe reasonable charges, and it is not bound to fix uniform rates for all commodities or to secure the same percentage of profit on every sort of business. There are many factors to be considered,―differences in the articles transported, the care required, the risk assumed, the value of the service, and it is obviously important that there should be reasonable adjustments and classifications. Nor is its authority hampered by the necessity of establishing such minute distinctions that the effective exercise of the rate-making power becomes impossible. It is not bound to prescribe separate rates for every individual service performed, but it may group services by fixing rates for classes of traffic. As repeatedly observed, we do not sit as a revisory board to substitute our judgment for that of the legislature, or its administrative agent, as to matters within its province. San Diego Land & Town Co. v. Jasper, 189 U. S. 439; Louisville & Nashville R. R. v. Garrett, 231 U. S. 298, 313. The court, therefore, is not called upon to concern itself with mere details of a schedule; or to review a particular tariff or schedule which yields substantial compensation for the services it embraces, when the profitableness of the intrastate business as a whole is not involved. But a different question arises when the State has segregated a commodity, or a class of traffic, and has attempted to compel the carrier to transport it at a loss or without substantial compensation even though the entire traffic to which the rate is applied is taken into account. On that fact being satisfactorily established, the presumption of reasonableness is rebutted. If in such a case there exists any practice, or what may be taken to be (broadly speaking) a standard of rates with respect to that traffic, in the light of which it is insisted that the rate should still be regarded as reasonable, that should be made to appear. As has been said, it does not appear here. Frequently, attacks upon state rates have raised the question as to the profitableness of the entire intrastate business under the State's requirements. But the decisions in this class of cases (which we have cited in the margin 1) furnish no ground for saying that the State may set apart a commodity or a special class of traffic and impose upon it any rate it pleases, provided only that the return from the entire intrastate business is adequate. In St. Louis & San Francisco Ry. v. Gill, 156 U. S. 649, a statute fixing a maximum rate for passengers in the State of Arkansas was challenged, but the allegation and offer of proof that the rate would compel the carriage of passengers at a loss related only to a portion, or division, of the railroad and not to the result of all the traffic to which the rate in question applied. The holding that this was insufficient was in entire accord with the above stated principle, that the rate-making power may be exercised in a practical way and that the legislature is not bound to assure a net profit from 'every mile, section, or other part into which the road might be divided.' Id., p. 665. A passenger rate may apply generally throughout the State, and the effect of the rate must be considered with respect to the whole business governed by the rate. In Smyth v. Ames, 169 U. S. 466, a schedule of freight rates was involved, and, while the entire schedule was under consideration, it was recognized that in order to determine its adequacy the 1 Stone v. Farmers' Loan & Trust Co., 116 U. S. 307; Dow v. Beidleman, 125 U. S. 680, 690; Chicago & Grand Trunk Ry. v. Wellman, 143 U. S. 339, 341; Reagan v. Farmers' Loan & Trust Co., 154 U. S. 362; Covington & Lexington Turnpike Co. v. Sandford, 164 U. S. 578; Smyth v. Ames, 169 U. S. 466; S. C., 171 U. S. 361; San Diego Land & Town Co. v. National City, 174 U. S. 739; Chicago, Milwaukee & St. Paul Ry. v. Tompkins, 176 U. S. 167; San Diego Land & Town Co. v. Jasper, supra; Stanislaus County v. San Joaquin Canal Co., 192 U. S. 201; Knoxville v. Knoxville Water Co., 212 U. S. 1; Willcox v. Consolidated Gas Co., 212 U. S. 19; Cedar Rapids Gas Co. v. Cedar Rapids, 223 U. S. 655; Louisville v. Cumberland Telephone & Telegraph Co., 225 U. S. 430; Minnesota Rate Cases, 230 U. S. 352, 433; Missouri Rate Cases, 230 U. S. 474, 497; Southern Pacific Co. v. Campbell, 230 U. S. 537; Allen v. St. Louis, Iron Mountain & Southern Ry., 230 U. S. 553, 556. 236 U. S. Opinion of the Court. intrastate freight business might be segregated. Id., pp. 535, 550. The case of Minneapolis & St. Louis R. R. v. Minnesota, 186 U. S. 257, involved a rate fixed by the Railroad and Warehouse Commission of the State of Minnesota for the intrastate transportation of hard coal in carload lots. There was no proof that the carrier was compelled to transport the coal at a loss or without substantial compensation. The principal testimony, as the court observed, was intended to show that 'if the rate fixed by the Commission for coal in carload lots were applied to all freight, the road would not pay its operating expenses, although in making this showing the interest upon the bonded debt and the dividends were included as part of the operating expenses.' It was said that it was 'quite evident' that this testimony had 'but a slight, if any, tendency to show that even at the rates fixed by the Commission there would not still be a reasonable profit upon coal so carried' (id., p. 266); and this conclusion effectually distinguishes the case from the one at bar. In Interstate Street Ry. v. Commonwealth, 207 U. S. 79, 84, the decision rested upon the ground that the charter of the company was accepted subject to the obligations imposed by the statute there in question. In Willcox v. Consolidated Gas Co., 212 U. S. 19, in addition to the rate for gas supplied for general consumption in the City of New York, there was a lower rate fixed for that furnished to the City itself. It was said by the court that the criticism of the 'wholesale' rate to the City was met by the fact that the total returns from the sale of gas were adequate. It was not established in that case that this 'wholesale' rate required a service without substantial compensation in addition to cost. It has repeatedly been assumed in the decisions of this court, that the State has no arbitrary power over the carrier's rates and may not select a particular commodity or class of traffic for carriage without reasonable reward. Opinion of the Court. 236 U. S. In Atlantic Coast Line R. R. v. Florida, 203 U. S. 256, 260, and in Seaboard Air Line Railway v. Florida, 203 U. S. 261, 270, there was an attack upon a rate on a single article, to wit, on phosphates, but the proof as to the effect of the rate and the cost of the transportation was found to be insufficient. The case of Atlantic Coast Line R. R. v. North Carolina Corporation Commission, 206 U. S. 1, involved the validity of an order of the State Commission requiring the railroad company so to arrange its schedule of transportation between two points as to make connections with through trains. It was held that the order merely compelled the carrier to perform a duty which fell within the scope of the obligations it had assumed. So far from the case being an authority for the conclusion that the validity of a particular rate cannot in any case be challenged if the return from the entire intrastate operations are deemed to be adequate, the court in the course of its opinion expressly conceded the contrary. The court said (id., pp. 25, 26): "Let it be conceded that if a scheme of maximum rates was imposed by state authority, as a whole adequately remunerative, and yet that some of such rates were so unequal as to exceed the flexible limit of judgment which belongs to the power to fix rates, that is, transcended the limits of just classification and amounted to the creation of favored class or classes whom the carrier was compelled to serve at a loss, to the detriment of other class or classes upon whom the burden of such loss would fall, that such legislation would be so inherently unreasonable as to constitute a violation of the due process and equal protection clauses of the Fourteenth Amendment. Let it also be conceded that a like repugnancy to the Constitution of the United States would arise from an order made in the exercise of the power to fix a rate when the result of the enforcement of such order would be to compel a carrier to serve for a wholly inadequate compensation a class or |