(dissenting in part).
I concur in the view that the Frederick-son patent is invalid; but I think that the Robinson & Moore patents should be sustained. They filled a long existing want in the industry; they solved a problem to which skilled workers in the industry had long addressed themselves in vain; they provided a product which secured the approval of the underwriters’ laboratories, which could be manufactured more cheaply than the products theretofore approved and which for that reason entered into general *91use and achieved marked commercial success ; and they embodied a combination of elements which I do not think had been anticipated in the art.
The nature of the braided jacket and the spirally wrapped serving, used by the industry as a covering for rubber-covered building wire, with the disadvantages to which both were subject, are set forth in the opinion of the court. There were many efforts to find a solution which would eliminate the disadvantages of the braid on the one hand and the serving on the other. McCulloch patent 1,216,337 of 1917, applied for in 1912, was a direct attack on the problem. It proposed interlacing the turns of the serving with either lengthwise or helical threads; but this failed to solve the problem. It did not offer the speed of application of a plain serving because it retained to some extent the crossing of threads as in braiding, and had other disadvantages inherent in that process. The Western Electric Company, in 1926, secured Lamplough patent No. 1,610,954, the scheme of which was to place a serving around the rubber covered wire and then pass the wire through a hot bath, the heat of the solution softening the rubber so that the threads would adhere to it. This attempt likewise was unsuccessful, and Western Electric switched its efforts to improving the braiding machine, developing one twice as fast as those previously used. An approach similar to that of Western Electric was made by National itself when in 1933 it secured the Frederickson patent 1,900,-492, which proposed a pitch coating to aid the adhesion of the serving to the rubber; but the result was a failure which did not secure the approval of the underwriters’ laboratories.
The Robinson & Moore patents successfully solved the problem with which the industry had been struggling for more than two decades, i.e. they provided a covering for insulated wire which could be applied as rapidly as the spirally wound servings and which would meet the requisite safety standards. The solution was found in the use with the wrapping of servings of the reversely wound locking or binding thread, which holds the servings in place on the wire-when it is bent or twisted and prevents the opening of the servings and the resulting fracture of the protective covering. The National Board of Fire Underwriters approved the covering as sufficiently safe for inside wiring, and it entered immediately into extensive use and achieved marked commercial success. Though inferior in some respects to the braided jacket, it met the standard of safety of the Fire Underwriters and could be produced much more quickly and at less cost. The evidence shows that the use of the process of the patent has resulted in a four-fold increase in production per machine, with attendant economy in space, power and labor, as compared with the braiders formerly used. There is a further economy in cost of materials, as the process of the patents uses less cotton while giving a better coverage.
From what has been said it is clear that, while the elements of the combination for which the patents were granted were old, the combination itself was new and useful and resulted in a decided advance in the art. Under such circumstances I think there can be no doubt as to its being patentable ; but, if there were doubt, the doubt should unquestionably be resolved in favor of the validity of the patents. To the ordinary presumption of novelty arising from the grant of the patents must be added the fact that the invention filled a long felt want in the industry and entered into immediate use. Temco Co. v. Apco, 275 U. S. 319, 324, 48 S.Ct. 170, 72 L.Ed. 298; Diamond Rubber Co. v. Consolidated Tire Co. 220 U.S. 428, 31 S.Ct. 444, 55 L.Ed. 527. And in addition to this, there is the presumption arising from the imitation of the patented article by Triangle. As to this, I agree with what was said by Judge Hough, speaking for the Circuit Court of Appeals of the Second Circuit in Kurtz v. Belle Hat Lining Co., 2 Cir., 280 F. 277, 281: “The imitation of a thing patented by a defendant, who denies invention, has often been regarded, perhaps especially in this circuit, as conclusive evidence of what the defendant thinks of the patent, and persuasive of" what the rest of the world ought to think.” See also Hoeltke, v. C. M. Kemp Mfg. Co., 4 Cir. 80 F.2d 912, 919.
I do not think that British patent No. 242,911 to Roberts, granted in 1925, is an anticipation. That patent dealt with an entirely different problem and in an entirely different way. It related to paper insulation for electric cables; and the gist of the invention was to insulate the cable by applying layers of paper over it with wrappers or bindings of paper or thread between the layers for the stated purpose *92of separating them. Here the problem is to hold the servings of thread in place when the wire is bent or kinked and the thread used as a binder operates in an entirely different way and for an entirely different purpose from the wrappers or bindings of Roberts. The elements of the patents are different and their coaction is different. So different, in fact, is the one from the other that during the twenty-five years that various persons, including the Western Electric Company, were looking for a- solution of the problem it never occurred to anyone to think that Roberts furnished the solution.
And I do not think, as argued by counsel, that what the patentees did was so simple as not to involve invention. As said by the Supreme Court in Diamond Rubber Co. v. Consolidated Tire Co., supra, “Knowledge after the event is always easy, and problems once solved present no difficulties, indeed, may be represented as never having had any, and expert witnesses may be brought forward to show that the new thing which seemed to have eluded the search of the world was always ready at hand and easy to be seen by a merely skilful attention. But the law has other tests of invention than subtle conjectures of what might have been seen and yet was not. It regards a change as evidence of novelty, the acceptance and utility of a change as a further evidence, even as demonstration.” See 220 U.S. 428 at page 435, 31 S.Ct. 444, at page 447, 55 L.Ed. 527. The reason for this rule was well put by Mr. Justice (now Chief Justice) Stone in Paramount Publix Corporation v. American Tri-Ergon Corporation 294 U.S. 464, 474, 55 S.Ct. 449, 454, 79 L.Ed. 997, where he said: “Where the method or device satisfies an old and recognized want, invention is to be inferred, rather than the exercise of mechanical skill. For mere skill of the art would normally have been called into action by the generally known want.”
Nothing is more likely to lead courts into error, I think, than the subjective approach to the question of patentability in an attempt to say in the light of “knowledge after the event” whether a flash-of' genius was or was not present in what was done. While, of course, the courts are not to abdicate their common sense and the wisdom gained from experience, the approach to the question most likely to be correct is the objective one. The state of the prior art, the problem to which the invention was addressed, its success in solving the problem, its acceptance by the art and its success commercially, — these-should be accorded more weight than what a court, unfamiliar with the art or with the problems of industry generally, may chance to think, in the light of the problem’s solution, as to what one skilled in the art should have known or should have been able to do. When an inventor has really done something, when he has really solved1 a problem that has baffled an industry,, when he has added to the sum total of human knowledge or produced something new. of real service to an art, he is entitled to the protection of the patent laws and deserves better than to be told in the language of “knowledge after the event” that he has done nothing that anyone with the ordinary skill of the calling might not have done.
This is merely to say what was said better by Mr. Justice Day in Expanded Metal Co. v. Bradford 214 U.S. 366, 381, 29 S.Ct. 652, 655, 53 L.Ed. 1034: “It is often difficult to determine whether a given improvement is a mere mechanical advance, or the result of the exercise of the creative faculty amounting to a meritorious invention. The fact that the invention seems simple after it is made does not determine the question; if this were the rule, many of the most beneficial patents would be stricken down. It may be safely said that if those skilled in the mechanical arts are working in a given field, and have failed, after repeated efforts, to discover a certain new and useful improvement that he who-first makes the discovery has done more than the obvious improvement which would suggest itself to a mechanic skilled in the art, and is entitled to protection as an inventor.”
Judge Learned Hand expressed the same thought recently in the case of Bresnick v. United States Vitamin Corporation, 2 Cir.,, 139 F.2d 239, 241, where he said:
“We have repeatedly said that in judging whether a new combination is an invention,, we regard the history of the art as of much greater importance than our own untutored judgment as to what advances demand imaginative originality in specialized fields. Nothing can be less reliable than our naive-impressions based upon gross appearances;. the books never tire of warnings against *93them. We have not that acquaintance with the subject-matter which alone could give them any value; we should resort to them only when all other means have failed. In the case at bar the history of the art very clearly indicates that the problem of preserving and masking vitamins derived from fish livers was no different from that of doing the same to those derived from vegetables, or from mammalian livers. Certainly nothing suggests any difference. Yet even so, had the art waited long for the step (especially if there had been intermediate unsuccessful efforts) and if the step, when made, had been an answer for which the art had been looking, we might have yielded.”
The change wrought by Robinson & Moore over Roberts was certainly as great, if not greater, than the change involved in the paper making machine held patentable in Eibel Process Co. v. Minnesota & Ontario Paper Co., 261 U.S. 45, 43 S.Ct. 322, 67 L.Ed. 523.
And I do not think that this is a case in which commercial success can be ignored. It is true that commercial success resulted from the approval of the underwriters’ laboratories of a product which could be manufactured at less cost and therefore sold at a lower price than the product currently used; but the approval of the underwriters was obtained only as a result of the invention of the patent. The utility of the invention was that it provided a satisfactory product at a lower cost. It is manifest that utility within the meaning of the patent law need not reside in improvement of function. A new product which will do the work of the old and which can be produced at less labor or expense is a useful one within the meaning of the patent laws; and its commercial success cannot be ignored merely because attributable to cheapness rather than improved functioning. While commercial success alone is not sufficient to sustain the validity of a patent (Sylvania Industrial Corporation v. Visking Co. 4 Cir. 132 F.2d 947; Durand v. Bethlehem Steel Co. 3 Cir. 122 F.2d 321), it is a factor to be considered as persuasive of invention when the validity of the patent is doubtful. Textile Mach. Works v. Louis Hirsch Textile Machines 302 U.S. 490, 58 S.Ct. 291, 82 L.Ed. 382; Artcraft Silk Hosiery Mills v. Gotham Silk Hosiery Co., 3 Cir., 72 F.2d 47.