Opinion by
Henderson, J.,The refusal of the Public Service Commission to restrain the Penna. R. R. Company and the other railroad companies named in the complaint from increasing freight rates on shipments of pulp wood to the mills of the complainants at different places in Pennsylvania is the subject of this appeal. The rates were alleged to be unjust, unreasonable and discriminating and the prayer was for an order requiring the companies named to desist from charging the advanced rates. Section 4 of Article Y of the Public Service Company Act provides with reference to an inquiry in regard to an increase of rates as follows: “At any such hearing involving any proposed increase in any rate .the burden of proof to show that such increased rate is just and reasonable shall be upon the Public Service Company.” The obligation imposed by this provision of the statute was necessarily assumed by the railroad companies interested and the examination of the witnesses was conducted and the documentary evidence presented in accordance with this requirement. There is no statutory designation of the kind of evidence required to shift the burden of proof and it would be impracticable to specifically define the quantity necessary to produce that result. It must be sufficient, however, to satisfy a reasonable mind that the fact is as alleged. The record shows that a considerable volume of evidence was introduced at a regular hearing and that the case was disposed of by the commission after a consideration and review of that evidence. The sufficiency of the proof must be left in. a large degree to the sound judgment of the commission and where that judgment has been exercised on competent and relevant evidence the conclusion ought not to be disturbed by judicial interference unless it is made clearly to appear that it is unreasonable or not in conformity with law. *9At the hearing of an appeal the question for the court to determine is whether or not the order is reasonable and in conformity with law and in all such cases the orders of the commission are declared by the statute to be prima facie evidence of the reasonableness thereof and the burden of proving the contrary rests on the appellants. It was evidently not in legislative contemplátion to substitute the appellate court for the commission in the disposal of administrative questions. These are matters of fact to be determined according to the evidence. The decision of the commission is not to be set aside therefore merely on the consideration that it was not wisely made. The law vests in that body the authority to exercise its judgment and it is that rather than the opinion of this court which is to control the subject if the order be within the power of the commission and is not unreasonable. The power is not denied in this cáse and the only question therefore is whether the decision of the commission is an unreasonable exercise of «power. After a review of the evidence we are unable to find substantial grounds on which to rest the conclusion that the order entered is so manifestly unreasonable as to justify its reversal. The difficulty of ascertaining the cost of transportation of a single commodity even approximately is manifest. Such an inquiry would involve an investigation of the entire transportation business of the company and the reasonable profit to which its capital was entitled.
A system of classification with reference to kind, value, perishability, etc., forms a basis on which rates are commonly established and some of the evidence presented to the commission gives support to their conclusion that the rate for pulp wood had been for about fifteen years too low in comparison with that on other mérchandise of a generally similar character. We do not deem it necessary to discuss the evidence at length. That would be advisable if the case were to be disposed of on an inquiry whether in our opinion the weight of the evidence presented to the commission favored the position taken by *10the complainants, but we are not invested with authority to retry the case from this point of view. It is sufficient to say that we are not convinced by an examination of the evidence that the order is unreasonable within the meaning of the statute.
The appeal is therefore dismissed at the cost of the appellants.