This suit was brought to enjoin the enforcement of a rate of $3.40 fixed by the Interstate Commerce Commission on rough green fir lumber and laths carried by the complainant railroad *964 companies from certain'points in the Willamette Valie}’, in Oregon, to San Francisco and adjacent points; the Southern Pacific Company ' having on the 18th day of April, 1907, advanced its theretofore established rate on such lumber for such haul from $3.10 to $5 per ton. The pleadings, as changed since the cause was last presented to the court, no longer raise the point, then made, that the rates so fixed were below the cost of transporting the lumber.

It is well-established law that the fixing of the rates to be charged by public service corporations is a legislative function, from which it necessarily follows that when Congress, as it did, conferred upon the Interstate Commerce Commission the power, in causes properly brought before it, to determine what are and should be reasonable rates to be charged by the carriers of interstate commerce, its action in the premises is conclusive upon the courts, subject of course always to the inhibitions of the Constitution of the United States, which protect such companies, like everybody else, against confiscatory rates. In the case in hand, the main point relied upon by the counsel for the complainants at the bar was that it appears upon the face of the findings and decision of the Commission itself, that it did not fix the rate of $3.40 on the lumber in question as a reasonable rate, in and of itself, but only as a reasonable rate in view of the conduct of the railroad company, under and by reason of which the complainants established their mills and produced the traffic. We do not so interpret the findings and report of the Commission. It appears that the rate so fixed by the railroad company as an inducement to the lumbermen of the Willamette Valley to establish mills there for the production of lumber for transportation to San Francisco and other points was $3.10, which rate was continued for a number of years, and under which numerous mills were established by the lumbermen and a large amount of lumber produced by them and transported by the railroad companies. In respect to that matter, what the case shows is thus briefly stated by the Interstate Commerce Commission:

While it will be seen from the foregoing quotation from the report of the Commission that that body took into consideration the conduct of the railroad company under which the lumbennen undertook and developed the lumber industry in the Willamette Valley, the Commission, in fixing as it did the rate of $3.4=0 on rough green fir lumber and' laths for the haul in question, by no means limited the basis of its decision to the past action of the railroad companies, as will be seen from this further quotation from its findings and decision:

It will be seen from the last quotation from the findings of the Commission and from other parts of it that it expressly found that the old rate of $3.10 established by the railroad company paid an average return to it of about 5 mills per ton mile, and that while that rate was a low one “it did yield when established, has ever since yielded, and would for the future yield, a substantial return over and above the cost of operation.” In view of that finding, we cannot say that its increased rate to $3.40 a ton is so unreasonable as to come within any inhibition of the Constitution of the. United States. The jurisdiction which is invoked here ought, as was said by the Supreme Court of the United States in a recent and analogous case, to be exercised only in the clearest cases. The case referred to is a water rate case (Knoxville v. Water Company, 242 U. S. 1 , 29 Sup. Ct. 148, 53 L. Ed. 371 ), where the court said, among other things:

And the Supreme Court, in Knoxville v. Water Company, concluded its opinion in these timely and appropriate words:

The conclusion to which we have come in the case before us is that the complaint should he dismissed at the complainants’ cost. It is so ordered.