“ If the railroad companies in fact received their compensation for carriage from the sum retained by the coal companies as was claimed, then, whether they realized more or less than their published rates depended upon the price of coal. Taking the prices at times as shown in the statements filed with the Commission, it is apparent that the 35 per cent was less than published rates, and if that was the sum received for transportation, would work a discrimination against coal companies not having such contracts, and paying the full rate. ”

“ On the other hand, if the coal companies paid the full rate, and failed to realize as much from the percentage of the selling price retained, they would be losing money, and as they were owned by the railroad companies the loss would be ultimately theirs, and not the coal companies. It may be that the Commission or the courts will ultimately find that these contracts do not fix the compensation received by the carriers, and that, as claimed, the full rate is paid by these purchasing companies, and if there is a loss on these contracts it is made up in other business ”

“ To unreasonably hamper the Commission by narrowing its field of inquiry beyond the requirements of the due protection of rights of citizens will be to seriously impair its usefulness and prevent a realization of the salutary purposes for which it was established by Congress.
An appeal is also prosecuted from the refusal of the circuit court to order the witnesses Eben B. Thomas and William H. Truesdale to answer certain questions respecting the prices and sale of coal. ”

“ The railroads are all engaged in interstate commerce, and into their affairs and methods of doing business the Commission might be, and is, lawfully authorized by the commerce act to make investigation. ”

“ The coal is purchased by companies owned by the railroads, for which payment is made on the basis of 65 per cent of the general average price received at tidewater by the sale of sizes above pea coal, leaving 35 per cent for the purchaser, from which he must pay transportation charges and cost of sale. Here is a railroad company engaged at once in the purchase of coal through a company which it practically owns and the transportation of the same coal through different states to the seaboard. ”

“ Relevancy does not depend upon the conclusiveness of the testimony offered, but upon its legitimate tendency to establish a controverted fact. Relevancy is that 'quality of evidence which renders it properly applicable in determining the truth or falsity of the matter in issue between the parties to a suit.' 1 Bouvier Law Dict. ”

“ Furthermore, we think the testimony competent as bearing upon the manner in which transportation rates are fixed, in view of determining the question of reasonableness of rates, into which the Commission has a right to inquire. ”

“ It is urged that the complainant before the Commission did not show any real interest in the case brought and that the proceeding should, for that reason, have been dismissed. It is provided in the Act to Regulate Commerce, § 13, that 'any person, firm, corporation,' etc., complaining of anything done or omitted to be done by any common carrier subject to the provisions of this act, in contravention of the provisions thereof, may apply to said Commission by petition, etc. ”

“ It was clearly competent for Congress, to that end, to invest the Commission with authority to require the attendance and testimony of witnesses, and the production of books, papers, tariffs, contracts, agreements, and documents relating to any matter legally committed to that body for investigation.'
In Interstate Commerce Commission v. Cincinnati, N. O. & T. P. R. Co. 167 U.S. 479, 506, 42 L. ed. 243, 255, 17 Sup. Ct. Rep. 896, 903, this court held that the Commission had no power to fix rates. ”