place. That this disc, so operating, is all that there is in Young's patent, all that is claimed, and all that an inspection of the drawing shows it to be, is confirmed by its history. It has been before the world for more than half a century, and obviously the world did not want it; for it has not used it, although it has been free to do so for many years.

We have stated what we think would be the conclusions of the ordinary intelligence as to Young's inventive idea, drawn from the reading of the specifications and from the inspection of the drawing; but there are certain mysteries in the patent law that the ordinary mind cannot penetrate, and we must seek illumination from the experts. Unhappily we cannot accept without reservation the opinions of the experts who have been examined as witnesses, for they are necessarily partisans of the side calling them, and essentially advocates, and their opinions are contradictory, and tend to perplex, instead of elucidating, although they appear to be gentlemen of great ability and deserved eminence. But we have in the record before us the opinion of some experts whose testimony cannot be impeached because of interest. We refer to the trained officials of the Patent Office, who had the same question before them, and substantially the same arguments, when Hall filed his petition of interference on Painter's application for reissue, on the ground that Painter had been anticipated by Young. One of the primary examiners, Mr. Witherspoon, who has been examined as an expert by the defendants in this case, sustained this contention; but he was overruled by the unanimous judgment of the Board of Appeals. The case was exhaustively presented and carefully considered. We referred to these proceedings in our former opinion, and it is not necessary to repeat what was then said. The final decision of the board of examiners was that the "British patent cited has not this type of stopper, and does not include its elements operating in the same way to produce the same result."

In the former case one of the defenses set up in the answer was that Painter's patents "are void for want of novelty, because the contrivance described and shown therein was, prior to William Painter's alleged invention thereof, patented to Mr. Young in the United Kingdom of Great Britain and Ireland, August 21, 1848, in letters patent No. 12,247." When that case came on to be heard this prior patent was not introduced in evidence; but it was before the court as part of the proceedings of the Patent Office, growing out of Hall's interference, and did not escape our attention. There is an implication, rather than a suggestion, that there was something suspicious, if not sinister, in the failure of the defendants in that case to introduce this patent in evidence. It would surely have been as good a defense there as it is claimed to be here, and the omission to present it naturally calls for explanation. That it was due to lack of acumen and zeal on the part of defendants' counsel can hardly be successfully claimed. This court bears willing witness to the ability and earnestness with which the defense in that case was conducted. Mr. Walker, the leading counsel for the defendants, and the author of the well-known text-book on Patent Law, seemed to us to have explored the whole domain of the patent law to find weapons of assault upon the Painter patent, and all the learning on that subject was exhausted. That Painter's claim with

stood these assaults seemed to us to be due to the fact that it stood upon an impregnable foundation. Inasmuch as certain testimony was offered by the defendants in this case in explanation of the reasons for the abandonment of this defense, Mr. Walker was called by the complainants as a witness in rebuttal, and testified as follows:

"No ulterior reason, or any reason aside from my judgment of want of merit in the Young defense, had any influence in causing that defense to be omitted from the evidence in the Aluminum Case."

Copies of his correspondence while engaged in preparing for the defense, giving in detail the reasons for this conclusion, are in the record, from which it appears that after repeated experiments by the expert, Mr. Lorenz, and after thorough analysis by Mr. Walker himself of the mechanical points which he found to be involved in the question, and a thorough study of the Young patent, he reached the conclusion that Young's combination was practically useless because it did "not provide any way to guide its conical disc into its groove fully and firmly enough to enable it to exert any material resistance to any tendency that the cork may have to be forced out of the bottle by pressure within the bottle." In his letter of February 2, 1899, he says:

"We find, on experiment, Young's cork will not expand his disc into its groove when it is cut on a line with the diameter of that groove, because, being yielding, the cork will suffer itself to be indented by the edge of the disc rather than force that disc outward into its groove. It is apparent to me that Young never made a stopper on that plan, or he would have discovered that it was necessary to not only give the shoulder under the cork a diameter smaller than that of the unexpanded disc, but also to give the shoulder immediately under the disc groove a diameter less than the unexpanded disc." And, after giving further details, he adds:

"For these reasons I am convinced that we must give up all hope of making a successful defense on Young, and it is never wise to make any invalid defense in a patent case, because such a defense reflects injuriously upon whatever valid defenses may be introduced in the same case."

The conclusions reached, with manifest reluctance, after careful experiments and thorough analysis by experienced counsel, vitally interested and evidently anxious to discover in Young's patent an anticipation of the Painter patent, and which, if found, would have been a successful defense against it, and the conviction that there was no merit in such defense, and the entire abandonment of the same after it had been set up in the answer, seems to us to be entitled to great weight as the opinions of experts against their interest. Opinions of experts generally, though given under oath, are but arguments in behalf of the side calling them. They are paid for generally as counsel is paid. These considerations cannot affect the weight of the opinions of Mr. Lorenz and Mr. Walker, given in circumstances which furnished every possible motive for reaching conclusions the converse of those actually reached, and their weight depends solely upon our estimate of their ability and skill. In somewhat of the same atmosphere must be weighed the opinion of the learned and conscientious judge below. His judgment in the former case had been adverse to the complainants, not, it is true, upon the precise point now at issue, but his opinion evidently was that the Painter patent was not entitled to the broad construction claimed for it. So when this case came before him, in so far as bias may be predicated

of a mind so singularly open and just, it might be thought that his inclination would be rather to limit than to expand the claims of Painter's patent, and his conclusion that Young's patent is not an anticipation of the invention of the patent in suit states tersely the point and essence of this controversy:

"But Young's is, after all, a different kind of stopper. His is a cork or plug, which is the stopper, and which is kept from coming out by a metal dise or cup. The complainants' is a metal disc, which is the stopper, made tight by its contact with the bottle by an elastic packing of cork or other material."

On the side of the complainants, then, we have Young's statement of invention and the drawing illustrating it, which is fundamentally different from Painter's, in that it is a cork retainer, and not a new device for stoppering bottles, as Painter's is. We have the proceedings of the Patent Office, with its repeated adjudications, after discussion and consideration of substantially the same argument as now presented, adverse to the contentions now urged, and where the claims of the Painter patent were framed and approved as adequately expressing the distinction between Painter's invention and Young's and all prior inventions. We have the opinion and judgment of an uncommonly able and experienced lawyer, founded upon experiments of his expert and his own analysis, in circumstances tending to give it the highest value, that there was no merit in Young's patent as a defense against Painter. We have the judgment of the court below to the same effect, and we have the undisputed fact that, although Young's patent was before the world for half a century, it had no effect upon the bottle-stopping industry. There is no evidence that it was ever used for any practical purpose, or that any inventor or manufacturer ever found in it suggestion of or inspiration for any new form of bottle stoppers; and we have the judgment of this court, the correctness of which is not questioned or impeached, that:

"Prior to the inventions hereinafter to be described, which are the subjectmatter of this controversy, the common method of stopping bottles was with cork, wood, rubber, or some other resilient material, inserted longitudinally into the neck of the bottle, and held there by its elastic, lateral pressure in frictional contact with the circumference, supplemented, in cases where gaseous liquids cause internal pressure, by wire or twine on the outside of the bottle head." 108 Fed. 847, 48 C. C. A. 72.

Such was our judgment as to the state of the art prior to Painter's invention, the testimony showing abundantly and conclusively that there was no practical method of sealing bottles which dispensed with the costly and inconvenient plug or cork; and there is nothing in the testimony in this case, or in the argument, which attempts to modify the correctness of that conclusion. There have been great improvements in the art since Painter first received his patent, such as Hall's, who was a sort of pupil of Painter, and whose patent was held to be infringement, and the patents now in controversy, admitted to be infringements, if Painter's patent is construed as we have heretofore construed it. The fact that from the time of Young, in 1848, up to the time of Painter, there were no improvements in the art, and that since Painter's invention there have been many improvements, creates a strong presumption that Young's inventive idea was a barren one, and that

Painter's inventive idea was a different and a fruitful one, and the converse of a suggestion of identity of ideas, upon which the defense

rests.

Before considering further this defense it is well to state precisely what Painter's invention was. The pertinent claims are as follows:

"(1) The combination of a receptacle having a groove in the side of its mouth and a shoulder projecting inward beyond the wall of the mouth above the groove, and a cup-shaped disc or plate of material having permanent flexion, all operating as set forth."

"(4) The combination of a receptacle having a groove in the inside of its mouth and a shoulder projecting inward beyond the wall of the mouth of the groove, a cup-shaped disc or plate of material having permanent flexion, and a packing or stopper beneath and retained by the disc or plate, all operating as set forth.

"(5) A combination, substantially as hereinbefore described, of a bottle having an interior groove in its mouth, a packing or gasket in said groove, and a disc or plate of material having permanent flexion, which confines the packing in said groove, and maintains it in tight contact with the adjacent surface of the groove."

Figure 1 is a central section of the bottle neck, having a groove and a packing in such groove, and showing stopper in position to be expanded. Figure 2 is a similar section, showing the same expanded, and with the packing in the groove compressed and clamped against the adjacent surface of the groove. Figure 6 shows a cup-shaped disc. Reading his statement of invention and the figures illustrating it, what would the ordinary mind conceive to be the inventive idea of Painter? Clearly, his idea is to dispense with the old-fashioned method of stopping bottles with cork, and to produce by machinery a substitute for it. It is not intended to be an improvement on the old system, but a radical departure from it. Starting out with the knowledge that cork, being a natural product, was liable to great departures from uniformity in size and quality, relatively expensive in first cost, and requiring treatment to bring it to a satisfactory degree of elasticity, with certain disadvantages of a hygienic nature, by reason of its porous quality, which causes it to absorb deleterious substances, which might be injurious to the contents of the bottle, and which would also be injuriously affected by defective corks, requiring labor to put them in and additional labor to pull them out, he conceived a broadly novel system for stopper

ing bottles, by dispensing with cork or reducing its use to a minimum, which would be free from the erratic effects of the natural material, inexpensive to produce, facile to operate, and efficient in results. Young's whole conception being that a cork is necessary, there is no suggestion of a substitute for it. The inventive idea involved in his disc of metal is to provide a substitute for the wire caging to hold the cork in its place. It proceeds upon the theory that a cork is necessary, and therein lies the fundamental difference in the underlying principle between Young and Painter. The elements employed, in their relation to each other, in their methods of operating, and in results obtained, are essentially dissimilar; the difference being a difference in the plan, not merely a difference of proportion and degree in carrying out the same plan. Painter's plan involves an interior annular groove in the bottle neck, which forms the chamber for the stopper, with the shoulder which forms the floor, another shoulder which forms the roof, and a peripheral wall. The stopper is a cup-shaped disc, formed of material. having permanent flexion, small enough to enter the mouth of the bottle into the zone of the groove. When it so enters, being composed of material which retains its form when flattened, it is expanded by molecular deformation of the cup, whose periphery is pressed into hard and tight contact with the peripheral wall of the groove. If this wall was absolutely accurate in form, nothing more would be needed; but, as such refined nicety is expensive and difficult of attainment in ordinary bottles, Painter's scheme provides for supplementing the deflected cup with a packing of rubber, cork, or other suitable material, in the form of a gasket around the edges, and by the radial compression of this packing between the periphery of the cup and the peripheral wall of the groove; the disc serving not only its own office as a stopper, but also maintaining the packing in the groove in close contact with the adjacent surface of the bottle neck, thus making a stopper sufficiently tight to retain gaseous liquids. There is an inwardly projecting annular shoulder in the bottle neck, which prevents the cup slipping down too low in the neck of the bottle. A like shoulder above prevents it being pressed upwards by the expansion of the gaseous elements, and the cup thus easily positioned in the zone of the groove, when the deflecting agent is brought to bear on it, its periphery is expanded exactly where it is wanted. In such position it would be difficult to get it wrong. The packing required to make a tight joint need be very thin. If of cork, its bulk is trifling as compared with the amount of cork needed for an ordinary stopper; thus conserving economy and avoiding the other objections which experience has pointed out in the use of cork for stop

pers.

Claim 1 of Painter's patent does not refer to packing. Claim 4 recites the packing, and claim 5 recites a bottle having an interior groove in its mouth, with a packing or gasket and a disc or plate having permanent flexion. The battle raged for years in the Patent Office over these claims, and after thorough examination of all prior patents, including Young's, and exhaustive consideration of the whole subject, as shown by the record-some of Painter's claims being disallowed--the claims of the patent were framed and allowed by the board of appeals as adequately expressing such distinctions as that board finally determined would be effective for the purpose of securing the invention