Opinion of the Court. 225 U.S. Assuming, but without so deciding, that the state of the record was such as to justify the Circuit Court of Appeals in examining the evidence and determining whether it conclusively established the defense of contributory negligence, we come to consider whether that question was rightly decided. As is often true in such cases, some matters were not disputed at the trial, while others were the subjects of conflicting testimony or of testimony from which different inferences reasonably could be drawn. The matters not disputed were these: The injury occurred in the daytime, at a grade crossing in a small country village. The defendant's tracks, which were three in number, ran in a northerly and southerly direction and crossed the highway at right angles. About 700 feet south of the crossing the tracks curved to the west, and when cars were occupying the east track south of the crossing a traveler on the highway east of the crossing could not see a train approaching from the south on either of the other tracks. Mrs. Flannelly, one of the plaintiffs and wife of the other, had occasion to drive along the highway from her home, a few miles east of the railroad, to a point on the other side of it. Seated in the vehicle with her were two small boys. As she neared the crossing a freight train was approaching on the east track from the north. She stopped about 40 feet from that track and waited for the train to pass, which took some time, as it was long and moving slowly. Before this train obscured the view she looked along the tracks to the south and observed that no train was in sight coming from that direction. After the rear of the freight train passed about 150 feet beyond the crossing she drove to the first track, or near it, and, on looking in both directions and seeing no train approaching, started to drive over the tracks. Her view at that time extended 300 feet or more to the south along the second track. As she was passing over that track a passenger train approaching thereon from the south sounded a sharp danger signal, and soon struck a rear wheel of her vehicle, thereby wrecking the latter, inflicting bodily injuries on her, and killing one of the boys. The train was moving at a rate of from 50 to 60 miles an hour, or from 73 to 88 feet per second. There was also testimony, more or less disputed, from which the jury reasonably could have found that no whistle was sounded by the passenger train at the place where such a warning of its approach was usually and properly given; that the freight train came to a stop before Mrs. Flannelly drove on the tracks; that she listened attentively for signals given by approaching trains, but heard none, other than the danger signal which came too late to be of avail; that her horse became restive and nervous before she advanced to the crossing; that when the danger signal was sounded by the passenger train the horse halted, reared and delayed their progress between five and ten seconds; and that as that signal was sounded she saw the passenger train emerge from a volume of smoke or steam which was hanging over the tracks to the south. The law requires of one going upon or over a railroad crossing the exercise of such care for his own protection as a reasonably prudent person ordinarily would take in the same or like circumstances, including the use of his faculties of sight and hearing. And, generally speaking, whether such care has been exercised is a question of fact for the jury, especially if the evidence be conflicting or such that different inferences reasonably may be drawn from it. We think the evidence in this case, when tested by these standards, required that the defense of contributory negligence be submitted to the jury as a question of fact, as was done by the Circuit Court. The conclusion to the contrary in the Circuit Court of Appeals was rested upon the theory that the freight train did not stop after clearing the crossing but continued in a southerly direction, thereby giving promise that the obstruction to the view along the tracks on that side of the crossing would quickly disappear. But a careful examination of the record satisfies us that there was evidence from which the jury could well have found that the train came to a full stop about 150 feet south of the crossing before Mrs. Flannelly started to cross over. If it did, she hardly could be declared negligent for failing to await its further movements, of which she knew nothing. Besides, if the action of her horse was as described, she ought not to be charged with negligence in not anticipating it. Other questions were discussed at bar and in the briefs, but as, in the view which we take of the evidence examined by the Circuit Court of Appeals, the judgment of the Circuit Court should have been affirmed, the other questions need not be considered. Judgment reversed. WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY v. WAGNER ELECTRIC AND MANUFACTURING COMPANY. CERTIORARI TO THE CIRCUIT COURT OF APPEALS FOR THE EIGHTH CIRCUIT. No. 179. Argued March 1, 1912.-Decided June 7, 1912. Where the infringer has sold or used a patented article, the patentee is entitled to recover all of the profits. Where a patent, though using old elements, gives the entire value to the combination, the patentee is entitled to recover from an infringer all the profits. Where profits are made by using an article patented as an entirety, the infringer is liable for all the profits, unless he can show, and the 225 U.S. Statement of the Case. burden is on him, that the profits are partly the result of some other things used by him. Elizabeth v. Pavement Co., 97 U. S. 126. Where the patent admittedly creates only a part of the profits, the patentee is only entitled to that part and he must apportion the infringer's profits and show by reliable and satisfactory evidence either what part of the profits are attributable to his patent or that the entire value of the infringing article is attributable to his patent. Garretson v. Clark, 111 U. S. 120. Congress has legislated, Rev. Stat., § 4921, with a view to affording the patentee ample redress against the infringer, but the general rule of law that the burden is on the one suing for profits to show that they had been made applies. The patent itself is evidence of the utility of the claim and an infringer is estopped from denying that it is of value. Where the plaintiff patentec shows that profits have been made by the use of his patent, but defendant proves that there were other clements contributing to the profits, it then devolves upon the plaintiff to apportion the amount of profits attributable to the use of his patent. Where the infringer, however, by commingling the elements renders it impossible for the patentee to meet the requirement of apportionment, the entire inseparable profit must be given to the patentee. In such a case, as in that of a trustec ex maleficio confusing gains, the loss should fall on the guilty and not on the innocent. This rule applies even if the patented device infringed did not preponderate the creation of profits. The owner of a small part of a fund is equally entitled to protection as the owner of a larger share. While the rule applied may ultimately shift the burden so as to cast it on the defendant, it is justly cast upon one who should bear it, as he wrought the confusion. Where on reversal, a decree for appellant would deprive appellee of the right to ruling on exceptions taken by him to the master's report which were not passed on by the court, and it appears that other questions of law were not passed on below, and also that material evidence was omitted, the case will be remanded with power to hear and determine on new testimony and for further proceedings not inconsistent with the opinion. 173 Fed. Rep. 361, reversed. THE current produced by an electric generator is of relatively low pressure, and for that reason it is impracticable to utilize it, for power purposes, more than five or Statement of the Case. 225 U. S. six miles from the central station. It was found, however, that this pressure, or voltage, could be increased by the use of a transformer or converter, consisting of a metal core, through and around which are wound primary insulated wires leading from the generator. Secondary wires, also insulated, are wound through and around the same core, and carried thence to the point of application. The voltage is increased or decreased according as the secondary wires are wrapped around the core more or less frequently than the primary wires. One of the consequences of thus transforming the current is the generation of heat. In small machines this is corrected by radiation, but in large ones the heat "ages" the iron, lessens the efficiency of the transformer and, in time, deteriorates the insulation around the wires. This latter result causes short circuits, makes it impracticable to take advantage of the increased voltage, and thus again restricts the area in which currents of more than 10 K. W. can be used for producing light and power. 112 Fed. Rep. 417. Many efforts were made to overcome this difficulty, but without success until July 12, 1887, when George Westinghouse, Jr., secured patent 366,362 for an "Electrical Converter," which, his application stated, was intended to prevent the converter becoming "overheated when employed for a long time in transforming currents of high electro motive force." Extracts from the specifications and claims are copied in the margin.1 1 "The core is preferably composed of thin plates of soft iron separated individually or in pairs from each other by thin sheets of paper or other insulating material. The plates are preferably constructed with two rectangular openings through which the wires pass. Each group of say five or six plates-is preferably separated from the succeeding group by air spaces. These may be produced by passing tubes, which may be of soft iron or other metal, or of vulcanized fibre, along the lengths of the plates. It may be sufficient in other cases to block the group of plates apart at intervals instead of |