Opinion of the Court. 244 U. S. even of novelty or of invention in the Wolhaupter plates is in their having flanges on the upper surface, on which it is intended the rail shall rest, for downward extending flanges on the under side and the rail abutting shoulder on the upper side are found in earlier patents in almost precisely the form which he gave to them. But such flanges on the upper surface of the Wolhaupter plate cannot constitute of themselves patentable invention or novelty, for it is very clear, as we have already said, that a resort to channels, grooves and corrugations was a familiar method of reducing the weight and thereby the cost of iron plates without decreasing their strength, long before the Wolhaupter patents, and this form was, therefore, one to which any skilful mechanic would turn to accomplish the purpose that Wolhaupter claimed for it, and that others did so resort to this form is sufficiently shown by reference to the Wells patent, No. 203,570 (1878), the Wilson, patent, No. 522,867 (1894) and the Dunham patent, No. 469,386 (1892). With these facts before him the most that can be said for the patents in suit is that they gave a somewhat different form to three features which were perfectly familiar and were similarly grouped in prior forms of tie-plates but without giving to any of them any new function and without accomplishing by them any new result. This brings the patents within the principle so often declared that "a mere carrying forward of the original thought, a change only in form, proportions, or degree, doing the same thing in the same way, by substantially the same means, with better results, is not such an invention as will sustain a patent." Roberts v. Ryer, 91 U. S. 150; Belding Mfg. Co. v. Challenge Corn Planter Co., 152 U. S. 100; Market Street Cable Ry. Co. v. Rowley, 155 U. S. 621, 629. The device involved in these patents is so simple and familiar in all of its forms that a description of it seems 1 244 U. S. Opinion of the Court. sufficient to visualize it to the reader, but cuts of it in various forms may be found in the reported decisions of this case, Railroad Supply Co. v. Elyria Iron & Steel Co., 213 Fed. Rep. 789, and in the report of the case, involving the same claims of the same patents, in the Seventh Circuit, to be found in Railroad Supply Co. v. Hart Steel Co., 193 Fed. Rep. 418 and 222 Fed. Rep. 261. Clearly persuaded as we are that the slight variations claimed for the patents in suit from the plates which had gone before do not constitute patentable invention we cannot consent to further extend this discussion by a minute comparison of them with earlier patents appearing in the record, but we content ourselves with adopting as comment not to be improved upon in such a case as we have here the following from a former decision of this court: "The design of the patent laws is to reward those who make some substantial discovery or invention, which adds to our knowledge and makes a step in advance in the useful arts. Such inventors are worthy of all favor. It was never the object of those laws to grant a monopoly for every trifling device, every shadow of a shade of an idea, which would naturally and spontaneously occur to any skilled mechanic or operator in the ordinary progress of manufactures. Such an indiscriminate creation of exclusive privileges tends rather to obstruct than to stimulate invention. It creates a class of speculative schemers who make it their business to watch the advancing wave of improvement, and gather its foam in the form of patented monopolies, which enable them to lay a heavy tax upon the industry of the country, without contributing anything to the real advancement of the arts. It embarrasses the honest pursuit of business with fears and apprehensions of concealed liens and unknown liabilities to lawsuits and vexatious accountings for profits made in good faith." Atlantic Works v. Brady, 107 U. S. 192, 200. We add that each of the patents of the petitioner being in terms for an "improvement in tie-plates," the state of the "prior art" as described in this opinion requires that they be limited strictly to the form described in the claims, and therefore the patents in suit, even if they had proved valid, would not have been infringed by the plates manufactured by the defendant. The decree of the Circuit Court of Appeals is Affirmed. MR. JUSTICE DAY did not take any part in the decision of this case. HART STEEL COMPANY ET AL. v. RAILROAD SUPPLY COMPANY. CERTIORARI TO THE CIRCUIT COURT OF APPEALS FOR THE SEVENTH CIRCUIT. No. 67. Argued April 17, 18, 1917. Decided May 21, 1917. A patent owner sued for infringement in two circuits, the defendants being, in one case, a corporation which manufactured the articles complained of, and, in the other, a second corporation whose shares were owned, and whose conduct was controlled, by the first and which, with its manager (joined with it as co-defendant), was acting as the selling agent of the first corporation under its authority and in its interest. The subject-matter and relief prayed were the same in both suits. Held, that there was such privity between the defendants that a judgment against the plaintiff rendered by the Circuit Court of Appeals in the suit against the manufacturer was res judicata as to the other suit, then pending before the Circuit Court of Appeals for the other circuit. A decree against the plaintiff in a patent infringement suit was affirmed by the Circuit Court of Appeals for the Sixth Circuit while its appeal 244 U. S. Opinion of the Court. from a like decree in another suit involving the same controversy was pending unheard before the Circuit Court of Appeals for the Seventh Circuit. Held, that a motion for an affirmance, seasonably made to the latter court and supported by certified copies of the record and journal entries in the other case, establishing legal identity of the subject-matter and privity of the parties, was a proper means of interposing the defense of res judicata, and that the motion should have been granted. 222 Fed. Rep. 261, reversed. THE case is stated in the opinion. Mr. Frederick P. Fish and Mr. Frank F. Reed, with whom Mr. Edward S. Rogers was on the briefs, for petitioners. Mr. Taylor E. Brown, with whom Mr. Clarence E. Mehlhope was on the brief, for respondent. MR. JUSTICE CLARKE delivered the opinion of the court. This suit is here on certiorari to review the decision of the Circuit Court of Appeals for the Seventh Circuit. On December 9, 1908, the respondent herein, The Railroad Supply Company, as owner of three United States patents, viz., Nos. 538,809, 691,332 and 721,644, filed a bill in the District Court for the Northern District of Illinois against The Hart Steel Company and Guilford S. Wood, praying that the defendants be restrained from infringing certain designated claims of its patents, which are described in their specifications as covering new and useful improvements in railway tie-plates. This case will be hereinafter referred to as the First Case. Three months later, on March 26, 1909, the same plaintiff commenced a second suit against The Elyria Iron & Steel Company in the District Court for the Northern District of Ohio, praying for the same relief with respect to the same claims of the same patents as in the First Case. Opinion of the Court. 244 U. S. The two bills differed only as to the parties defendant. The Elyria Iron & Steel Company, the defendant in the Second Case, was a manufacturing corporation and was the owner of all of the capital stock of The Hart Steel Company, the defendant in the First Case, which was the selling agent of the Elyria Company, and Wood was its manager. The same defenses being relied upon in the two cases, the evidence was taken in the first one, and by stipulation a carbon copy of it was filed in the second, and the same exhibits were used in the two. The claimed infringement consisted in the manufacture of a single order of tie-plates by the Elyria Company and the sale of them by the Hart Company, with Wood as its manager, to the Atchison, Topeka & Santa Fe Railroad Company. Such proceedings were had in the First Case that on December 18, 1911, the Circuit Court for the Northern District of Illinois decided that the construction or device sold by the defendants did not infringe the claims of the plaintiff's patents relied upon, and dismissed the bill for want of equity. In the Second Case such proceedings were had that on March 4, 1912, the District Court for the Northern District of Ohio entered precisely the same decree as was entered in the First Case. Each case was appealed to the appropriate Circuit Court of Appeals and on April 7, 1914, that court for the Sixth Circuit, in a carefully considered opinion, found the claims of the patents relied upon void for want of novelty and invention and affirmed the decision of the District Court. A petition for rehearing was denied on the thirtieth day of the following June. On the sixth day of October, 1914, the first day of the next ensuing term of the Circuit Court of Appeals for the Seventh Circuit, the defendants in the first suit, which |