(after stating the facts as above). [1] The gist of the testimony so taken under objection is that Hardie’s real invention was a truck adapted for use with any bolster then known, and particularly suited to that of the type of the Schaffer bolster, having column guides, but which cannot be inserted into the side-frames unless the opening is enlarged in the manner shown in the patent drawings. But as the purpose of this enlargement is not explained in the patent or file wrapper, and since the bolster shown in the patent needs no such enlargement (working just as well with a square opening), a situation results where the sole patentable novelty asserted resides in an element wholly without use or function, and which might just as well have been entirely omitted unless explained or aided by something outside the four corners of the patent itself. Erom this it will be seen how very important this testimony becomes. Without it the patent as now construed by appellees has no force or effect. It may well be called Ilardie’s reissue. Moreover, his story is most persuasive, almost pathetic. His car truck has been highly successful in the hands of his’ assignee, as evidenced by its enormous sales. The picture of the poor but brilliant inventor being cheated out of his valuable discovery by the misapprehension of his solicitors is an appealing one, well calculated to influence any court. It was said upon the argument that this testimony was taken without a shadow of doubt of its admissibility; and it is undeniable that evidence to show the patentee’s equities is very common in patent cases, while motions to strike out such evidence are correspondingly rare. Therefore the question of admissibility becomes a vital one upon which alone depends the validity of the patent.
The patent record in suit presents a case quite similar to that of a patent ambiguity in a contract, which, as Lord Bacon said, could not be “holpen by averment.” The enlarged opening appears in the patent drawings, and is referred to in the amended claims, but without any explanation of its purpose, or any suggestion of usefulness or function. After reading all there is in the patent, the uncertainty still remains. When the file wrapper is examined, it is found that the enlargement of the opening is made part of the amended claims, but why this was done is just as uncertain as before. The ambiguity is emphasized, but the doubt is not dispelled. So we have an element shown in the drawings, and counted on in the claims, whose purpose *944■ is • a mystery, entirely without any use or function. “A patent ambiguity is an uncertainty that arises at once on the reading of the contract. We do not have to wait until some other fact is brought to our knowledge before the uncertainty is apparent, but the doubt is suggested at once, and by the phrase itself.” Strong v. Waters, 27 App. Div. 299, 50 N. Y. Supp. 257. A latent ambiguity, on the other handi, is one brought out by extrinsic evidence, where the words, in themselves clear, apply equally well to two different things. Petrie v. Trustees, 158 N. Y. 458, 53 N. E. 216. “Nothing is clearer than the general rule,” said Judge Story, in Peisch v. Dickson, 1 Mason, 9, Fed. Cas. No. 10,911, that “latent ambiguities may be removed by parol evidence, for they arise from proof of the facts aliunde; and, where the doubt is created by parol evidence, it is reasonable that it should be removed in the same manner. But patent ambiguities exist in the contract itself; and if the language be too doubtful for any settled construction, by the admission of parol 'evidence, you create, and do not merely construe, the conti'act.”
[2] The question then arises whether the contract between the government and the patentee, expressed by the patent, must not be construed to exclude all reference to the enlarged opening. Hardie’s alleged use of the Schaffer bolster as an element of his invention was all before lie filed his application. He tried! to make it a part of his discovery, but through his solicitors’ failure to comprehend was unable ' to do so. Thereupon he abandoned the only forms of bolsters which could possibly have any functional connection with his real invention, and substituted an ancient form which in and of itself absolutely excluded the only use, function, or novel result he was seeking to obtain. On this basis the patent was issued, the contract made. To allow the patentee now, by parol testimony, to make a wholly different . contract, and obtain an entirely different grant, is utterly inadmissible. 'Even as against the government, the other party to the grant, this would be unauthorized by settled principle, and how much less should it be allowed against the public, in nó way bound or concluded by such grant.
In Osgood Dredgee Co. v. Metropolitan Dredging Co., 75 Fed. 670, 673, 21 C. C. A. 491, defendant’s declarations or admissions tending to show patentability were shown in evidence. “In that class of litigation in which the results can affect no interests except those of the parties to it, the court may well give weight to declarations of that nature;- but with reference to a patent for an invention, which is of ■public concern, such declarations are of little consequence and neither the inventor -nor the alleged infringer can be permitted to substitute his' own acts or opinions for the judgment of the court. It is a thoroughly well-settled principle of patent law that in clear cases the court may, of its own motion, adjudge a patent invalid, even if its invalidity is not set up by the alleged infringer. Much more would it refuse to be controlled by evidence of this kind which the complainant ' thus brings to our attention.”
“Were-it important to inquire which of these two men would be most likely to produce a' working machine having the necessary char*945'-"teristics, there can be little doubt that Mr. Brush would be chosen. Out such an inquiry seems irrelevant. The patent law cannot be administered along such.lines as these. Patents are formal grants controlled by carefully drawn statutes and strict rules, and. must be construed as other similar documents are construed. The court is not permitted to inquire what the patentee might have done or was capable of doing. The question is, What did he do? Conjecture and speculation are out of place in interpreting the claims of a patent.” Coxe, j., in Edison Electric Light Co. v. E. G. Bernard Co. (C. C.) 88 Fed. 267, 275.
On the other hand, the evidence may properly show the prior art, the problem presented to the inventor, and all the surrounding circumstances, in order that the specifications and claims may be read in the light of the inventor’s actual knowledge, and such information as the law imputes to him. Field, C. J., in Giant Powder Co. v. California Vigorit Powder Co. (C. C.) 4 Fed 720, 727, 728. Thus, a broad claim, when applied to the disclosures of the prior art (pre snmed to be known to the inventor), must be limited accordingly, Buies of construction must be applied, to learn what the claim means. A latent ambiguity arises, and to explain it the court may put itself in the position of the inventor, and seek to know what he knew, and what the law required him to know. But this is quite a different thing from allowing him, by testimony showing what he tried to do, and how he unfortunately failed, to make a new contract, based on evidence never disclosed either to the Patent Office or the public, and which never saw the light until it became necessary for his assignee to broaden the contract, and include something which the patentee gave up, even though he gave it up through mistake of law.
Two cases were cited on the argument in support of the contention that the testimony of Hardie is admissible. These were Ball & Socket Fastener Co. v. Kraetzer. 150 U. S. 111, 14 Sup. Ct. 48, 37 L. Ed. 1019, and Steward v. American Lava Co.. 215 U. S. 161, 30 Sup. Ct. 46, 54 L. Ed. 139. In both these cases, however, the testimony was rather in the nature of an admission, made against interest, and was not self-serving in its character, as were the persuasive explanations of the patentee in this case. Technically speaking, Hardie had no interest, because he. had assigned his patent; but his statements were not against his interest, he having none, but were in support of his assignee’s attempt to broaden the scope of the public disclosure of his specifications and claims.
Disregarding this evidence, as we must, we have the case, of an element not defined, vital to the validity of the patent as now construed by appellees, and which is utterly without function or use. Within the loosest construction of the statute requiring full, clear, concise description, the appellees’ contention respecting the lawful scope of the patent in suit cannot be sustained. Merrill v. Youmans, 94 U. S. 568, 24 L. Ed. 235; Bates v. Coe, 98 U. S. 31, 25 L. Ed. 68; Incandescent Lamp Patent, 159 U. S. 465, 16 Sup. Ct. 75, 40 L. Ed. 221.
Within the rules of Blease v. Garlington, 92 U. S. 1, 23 L. Ed. 521, and Nelson v. United States, 201 U. S. 92, 114, 26 Sup. Ct. 358, *94650 L. Ed. 673, settling the rule as to the return on appeal of inadmissible evidence taken below, defendant’s counsel might have movedl before hearing to strike out so much of Hardie’s testimony as related to his conferences with his solicitors, and to his real invention, or insisted on the hearing (as they did) upon the objection. Whatever action might have been taken by the court in either event, the evidence would nevertheless be part of the record on appeal, even if struck put by the trial judge. Under the cases cited, and by the common practice, all evidence taken, whether struck out or not, is to go up on appeal.
The decree appealed from is reversed, with direction to dismiss the bill for want of equity.