a reaping machine to the rake on the platform | fringement are determined in favor of the comof the machine, and in the method of hanging plainants or respondents. the reel so as to dispense with any post on the 538*] side of the machine next the grain, were also acquired by the appellants as a part of the same arrangement, and they charge in the bill of complaint that the second claim of the original letters patent, embodying that improvement, is also infringed by the respondents. Power to grant letters patent is conferred by law upon the Commissioner of Patents, and when that power has been lawfully exercised, and a patent has been duly granted, it is of itself prima facie evidence that the patentee is the original and first inventor of that which is therein described, and secured to him as his invention. White v. Allen, 2 Cliff. 228. Persons seeking redress for the unlawful use of letters patent, in which they have an interest, are obliged to allege and prove that they, or those under whom they claim, are the original and first inventors of the improvement embodied in the letters patent on which the suit is founded, and that the same have been infringed by the party against whom the suit is brought. Undoubtedly, the burden to establish both of those allegations is, in the first place, upon the party instituting the suit, as they lie at the foundation of every such claim, but the law is well settled that the let ters patent in question, where they are introduced in evidence in support of the claim, if they are in due form, afford a prima facie presumption that the first-named allegation is true, and the rule is equally well settled that that presumption, in the absence of satisfactory proof to the contrary, is sufficient to entitle the party instituting the suit to recover for the alleged violation of the exclusive rights secured to him in the letters patent. Availing themselves of that rule of law, the complainants in this case introduced the five several letters patent on which the suit is founded, and they contend and well contend that their effect as evidence is to cast the burden of proof upon the respondents to show that the respective patentees are not the original and 539] first inventors of the improvements *embodied in the several letters patent, as they have alleged in their answer. Parties defendant, sued as infringers, are not allowed in an action at law to set up the defense of a previous invention, knowledge, or use of the thing patented, unless they have given notice of such a defense thirty days before the trial, and have stated in the notice "the names and places of residence of those whom they intend to prove to have possessed a prior knowledge of the thing, and where the same had been used;" and the settled practice in equity is to require the respondent, as a condition precedent to such defense, to give the complainant substantially the same information in his answer. Agawam Co. v. Jordan, 7 Wall. 596, 19 L. ed. 177; Teese v. Huntingdon, 23 How. 10, 16 L. ed. 482. Notices of the kind were given by the respondents in this case, but it will be more convenient to examine certain special defenses set up in the answer before entering upon that in quiry, as the decree must be affirmed, in any event, if any one of those defenses is well founded, whether the issues of novelty and of in All of the special defenses apply to the original patent, as well as to those which have been reissued, except such as are founded upon the acts or omissions of the commissioner in granting the reissues, which of course are not applicable to the former. They are eight in number, as exhibited in the answer, the respondents alleging in each that the letters patent are void and of no effect for the reasons therein set forth; and they will be briefly examined in the order in which they are pleaded. 1. That the letters patent are void and of no effect because the patentees did not make oath before the patents were granted, that they did verily believe that they were the original and first inventors of the improvements for which the letters patent were solicited. Congress possesses the power to pass laws to secure to inventors, for limited times, the exclusive right to their inventions, and [*540 Congress, in pursuance of that article of the Constitution, has conferred the power to grant letters patent for that purpose upon the Commissioner of Patents. Persons who have made an invention, and who desire to obtain an exclusive property therein, may make application in writing to the Commissioner of Patents, and the provision is that the commissioner, on due proceedings had, may grant a patent for the said invention. Inventors of machines are required, before they receive a patent, to deliver a written description of their inventions, and of the manner and process of making, constructing, and using the same, in such "full, clear, and exact terms" as to enable any person skilled in the art or science to make, construct and use the same, and fully to explain the principle by which the invention may be distinguished from others of like kind; and they are also required to specify and point out the part, improvement or combination which they claim as their invention. Doubtless these several requirements may be regarded as conditions precedent to the right of the commissioner to grant the application, as they must appear on the face of the letters patent, and are always open to legal construction as to their sufficiency. Drawings are also required in certain cases, and where the invention is such that it may be represented by a model, the applicant for a patent is required to furnish a model of the same; make oath or affirmation that he does verily beand the further requirement is that he shall lieve that he is the original and first inventor of the improvement for which he solicits a patent, and that he does not know that the same was ever before known or used. Importance, it is conceded, must be attached to the latter requirement, but it is certain that the oath or affirmation may be taken elsewhere than before the commissioner, as the same section provides that it "may be made before any person authorized by law to administer oaths." 5 Stat. at L. 119. *Extended examinaton of the question, [*541 however, is unnecessary, as every one of the letters patent on which the suit is founded contains the recital that the required oath was taken before the same was granted, and the court is of the opinion that those recitals, in the absence of fraud, are conclusive evidence that the necessary oaths were taken by the applicants before the letters patent were granted. 2. That the letters patent are void and of no effect because the patentees did not specify and point out in their specifications and claims the parts, improvements or combinations which they claim as their respective inventions. Grant the theory of fact assumed in the proposition and the conclusion would follow, but the whole theory of the proposition as applied to the present case is founded in error. Inventions secured by letters patent sometimes, though rarely, embrace an entire machine, and in such cases it is sufficient if it appear that the claim is co-extensive with the invention. Other inventions embrace only one or more parts of a machine, as the coulter of a plough, or the divider or sweep rake of a reap ing machine; and in such cases the part or parts claimed must be specified and pointed out so that constructors, other inventors and the pub- | lic may know how to make the invention, and what is withdrawn from general use. id by reason of a defective or insufficient description or specification, if the error arose by inadvertency, accident or mistake, and without any fraudulent or deceptive intention, it is lawful for the commissioner, upon the surrender to him of such patent, and on the payment to him of a certain duty, to cause a new patent to be issued to the inventor for the same invention for the residue of the term then unexpired, in accordance with the patentee's corrected description and specification. 5 Stat. at L. 122. Whether adjudged to be valid or invalid, it is clear that the several re-issued let- [*543 ters patent are all in due form, and that they contain all the usual recitals asserting a compliance with the requirements specified in the Patent Act, and it is equally certain that the respondents did not introduce any proofs to establish the theory of fact assumed in the answer. Authority to accept the surrender of the original patents in certain cases, and to grant new patents to the inventor, was conferred upon the commissioner by the act of the 3d of July, 1832, and in a case arising under that act it was held by this court, more than thirty years ago, that where an act was to be done or a patent granted, upon proofs to be laid before a public officer, upon which he was to decide, the fact that such public officer had done the act or granted the patent was prima facie evidence that the proofs had been regularly made, and that they were satisfactory even though the patent did not contain any recitals that the perquisites to the grant had been fulfilled; and such continued to be the rule until the question came up again for consideration under the existing Patent Act, when it was held by this court that the fact of the granting of the re-issued patent closed all inquiry into the existence of inadvertence, acciof fraud for the jury. Patented inventions are also made which embrace both a new ingredient and a combination of old ingredients embodied in the same machine. Even more particularity of description is required in such a case, as the property of the patentee consists, not only in the new ingredient, but also in the new combination, and it is essential that his invention shall be so fully described that others may not be led into mistake, as no other person can lawfully make, use or vend a machine containing such new ingredient, or such new combination. They may make, use or vend the machine without the patented improvements, if it is capable of such use, but they cannot use either of those improvements without making themselves liable as in-dent or mistake, and left open only the question fringers. R. R. v. Stimpson, 14 Pet. 458; Stimpson v. R. R. 4 How. 384; 4 Stat. at L. 559. 542*] *Improvements in machines protect. Fish. Pat. Cas. 605. Since that time it has been definitively settled that neither re-issued nor extended patents can be abrogated by an infringer, in a suit against him for infringement, upon the ground that the letters patent were procured by fraud in prosecuting the application for the same before the Rubber Co. V. Goodyear, 9 Wall. 797, 19 L. ed. 569, 2 Cliff. 375. Where the commissioner accepts a surrender of an original patent and grants a new patent, his decision in the premises, in a suit for infringement, is final and conclusive, and is not re-examinable in such a suit in the circuit court, unless it is apparent upon the face of the patent that he has exceeded his authority, that there is such a repugnancy between *the [*544 old and the new patent that it must be held, as matter of legal construction, that the new patpre-ent is not for the same invention as that embraced and secured in the original patent. Battin v. Taggert, 17 How. 83, 15 L. ed. 40; O'Reilly v. Morse, 15 How. 111, 112; Sickles v. Evans, 2 Cliff. 222; Allen v. Blunt, 3 Story, 744. Such a combination is sufficiently described if the ingredients of which it is composed are named, their mode of operation given, and the new and useful result to be accomplished pointed out, so that those skilled in the art and the public may know the extent and nature of the claim and what the parts are which co-operate to produce the described new and useful result. Tested by these rules, it is clear that the objection under consideration cannot vail in respect to any one of the several letters patent on which the suit is founded. 3. That the re-issued letters patent are void and of no effect, because the Commissioner of Patents never obtained jurisdiction to receive the surrender of the originals, nor to grant the re-issues, as no evidence was produced before him to show that the originals were inoperative or invalid for any reason or cause whatsoever. Whenever any patent is inoperative or inval 4. That the re-issued letters patent are void and of no effect because they were not granted for the same invention as that embodied in the original letters patent, nor for any invention made by the patentees before the original letters patent were granted. original patent are void and of no effect, as no jurisdiction to grant such a patent is conferred by any act of Congress upon the commissioner, and he possesses no power in that behalf except what the acts of Congress confer. Whether a re-issued patent is for the same invention as that embodied in the original patent *or for a different one, is a question for [*546 the court in an equity suit to be determined as a matter of construction, on a comparison of the two instruments, aided or not by the testimony of expert witnesses, as it may or may not appear that one or both may contain technical terms or terms of art requiring such assistance in ascertaining the true meaning of the language employed. Sickles v. Evans, 2 Cliff. 203. Re-issued letters patent must, by the express | stantially different from that embodied in the words of the section authorizing the same, be for the same invention and, consequently, where it appears on a comparison of the two instruments, as matter of law, that the re-issued patent is not for the same invention as that embraced and secured in the original patent, the reissued patent is invaiid, as that state of facts shows that the commissioner, in granting the new patent, exceeded his jurisdiction. Power is, unquestionably, conferred upon the commissioner to allow the specification to be amended if the patent is inoperative or invalid, and in that event to issue the patent in proper form; and he may, doubtless, under that authority, allow the patentee to re-describe his invention and to include in the description and claims of the patent not only what was well described before, but whatever else was suggested or substantially indicated in the specification or drawings which properly belonged to the invention as actually made and perfected. Interpolations of new features, ingredients, or devices, which were neither described, suggested nor indicated in the original patent, or patent office model, are not allowed, as it is clear that the commissioner has no jurisdiction to grant a re-issue unless it be for the same invention as that embodied in the original letters patent, which, necessarily, excludes the right on such an application to open the case to new parol testimony and a new hearing as to the nature and extent of the improvement, except 545*] in certain special cases, as provided in* a recent enactment not applicable to the case before the court. 16 Stat. at L., 206; Cahart v. Austin, 2 Cliff., 536; Curt., Pat. (3d. ed.), 276; Woodworth v. Stone, 3 Story, 753. Corrections may be made in the description, specification or claim where the patentee has claimed as new more than he had a right to claim, or where the description, specification or claim is defective or insufficient, but he cannot, under such an application, make material additions to the invention which were not described, suggested, nor substantially indicated in the original specifications, drawings or patent office model. Prior to the decision of this court that a person sued as an infringer cannot abrogate a reissued or extended patent by showing that the commissioner had been induced to grant it by fraudulent representations, it had sometimes been supposed that every such new patent was open to that defense and that the question was one of fact dependant upon evidence, but since it has been determined that such a party cannot be heard to make such a defense to the charge of infringement, it has come to be regarded as the better opinion that all matters of fact involved in the hearing of an application to re-issue a patent, and in granting it, are conclusively settled by the decision of the commissioner granting the application. Matters of construction arising upon the face of the instrument are still open, but all matters of fact connected with the surrender and re-issue are closed in such a suit by the decision of the commissioner in granting the re-issued patent. Rubber Co. v. Goodyear, 9 Wall. 796, 19 L. ed. 568: Stimpson v. R. R. Co., 4 How. 404; R. R. Co. v. Stimpson, 14 Pet. 458. Letters patent re-issued for an invention sub Where the specification and claim, both in the original and re-issued patents, are expressed in ordinary language, without employing any technical terms or terms of art, the question whether the re-issued patent is for the same invention as that described in the original patent or for a different one, is purely a question of construction, but where both or either contain technical terms or terms of art the court may hear the testimony of scientific witnesses to aid the court in coming to a correct conclusion. Cases, doubtless, arise where the language of the specification and claim, both of the surrendered and re-issued patents, is so interspersed with technical terms and terms of art that the testimony of scientific witnesses is indispensable to a correct understanding of its meaning. Both parties in such a case would have a right to examine such witnesses, and it would undoubtedly be error in the court to reject the testimony, but the case before the court is not of a character to render it expedient to pursue the inquiry. Bischoff v. Wethered, 9 Wall. 814, 19 L. ed. 830; Betts v. Menzies, 4 B. & S., Q. B., 999. Apply the rule to the present case, that the question is one of construction, and it is clear that the defense under consideration is not open to the respondents, as they did not introduce in evidence the original letters patent from which the re-issued patents were derived. Persons owning re-issued letters patent, and seeking redress from those who have invaded their exclusive rights, are not obliged to introduce in evidence the surrendered patent, and if the old patent is not introduced by the party sued, he cannot have the benefit of such a defense. *5. That the several letters patent [*547 are void and of no effect because the claims therein patented are for an effect, and not for any particular machinery. as set Founded, as the defense is, upon an obvious misconstruction of the claims of the several patents, it does not seem to require much explanation. Omit the words "substantially as described," or "substantially forth," and the question presented would be a very different one, but inasmuch as those words, or words of equivalent import, are employed in each of the claims, the defense is without merit. Where the claim immediately follows the description of the invention it may be construed in connection with the explanations contained in the specifications, and where produces a new and useful result, then a patent may be granted for the same, and it will be upheld as a patentable improvement. Park v. Little, 3 Wash. (C. C.) 196. it contains words referring back to the specifi- | valuable use not known before, and it actually cations, it cannot properly be construed in any other way. Curt. Pat. (3d. ed.), §§ 225-227. 6. That the several re-issued letters patent are void and of no effect because the claims therein made are too broad and embrace that of which the patentees were not the original and first inventors prior to the granting of the original letters patent. Improvements for which a patent may be granted must be new and useful, with [*549 in the meaning of the patent law, or the patent will be void, but the requirement of the Patent Properly understood the defense is substan-Act in that respect is satisfied if the combinatially the same as that set up in the fourth defense, and it must be overruled for the same reasons, which need not be repeated. 7. That the several letters patent are void and of no effect because what is claimed therein as new was in public use, with the consent and allowance of the original patentees, more than two years before they applied for the several patents. Such a defense set up in a case where the complainants file the general replication is of no avail unless sustained by proof, and the respondents did not introduce any proofs to sustain it, which is all that need be said upon the subject. tion is new and the machine is capable of being beneficially used for the purpose for which it was designed, as the law does not require that it should be of such general utility as to supersede all other inventions in practice to accomplish the same object. Lowell v. Lewis, I Mason, 182; Bedford v. Hunt, 1 Mason, 302; Many v. Jagger, 1 Blatchf. 372; Barret v. Hall, 1 Mason, 447. Unsuccessful in those defenses, the respondents in the next place attack the respective inventions as destitute of originality, and allege that the patentees were not the original and first inventors of the several improvements supposed to be secured in the letters patent. Separate defenses of the kind are set up in the answer to each of the letters patent, but the nature and character of the objections are such that the whole series may properly be con 8. That the combination claimed in each of the several letters patent is a combination of old parts, the combining of which involved no invention, but merely the skill of an intelligent mechanic or other person skilled in the manu-sidered together. facture and use of harvesting machines. 548*] *Reduced to a proposition, the defense, as set up in the answer, is that the several improvements were old and not patentable on that account, as no improvements were made which required invention. Specific objection is made under this head to each of the four re-issued letters patent, but the grounds of the several objections are substantially the same, so that the several propositions may be considered together. New and useful machines are the proper subjects of an application for a patent, and so, by the express words of the act of Congress, are new and useful improvements on any machine. All of the patents embraced in the suit fall under the second clause of the provision, and are of the fourth class of patents before described, that is, they consist of a new combination of old elements whereby a new and useful result is obtained. Particular changes may be made in the construction and operation of an old machine so as to adapt it to a new and valuable use not known before, and to which the old machine had not been, and could not be, applied without those changes and, under those circumstances, if the machine, as changed and modified, produces a new and useful result, it may be patented, and the patent will be upheld under existing laws. Bray v. Hartshorn, 1 Cliff. 541; Losh v. Hague, 1 Web. Pat. Cas. 207; Hind. Pat. 95; Phillips v. Page, 24 How. 166, 16 L. ed. 640; Norm. Pat. 25. Prior notice in the answer is required in such a case as a condition precedent to the right to introduce proofs to support such a defense, and it is certainly proper that the respondent should be allowed to comply with that requirement, but it is an abuse of the privilege to give such notices without some reason to suppose that such a defense can successfully be made, and that the proofs, if required, can be obtained, as it exposes the complainant to unnecessary expense and trouble in preparing his case for trial. Where no proofs, were introduced in support of the answer no mention will be made of the notices, as a notice without proof to support it is of no avail. Out of all the alleged prior inventions set up in the answer, only four were made the subject of proof to any substantial extent. Two of these are the inventions of Obed Hussey and of Thomas D. Burral, of the combination of the quadrant shaped platform located behind the cutting apparatus. Those patents were introduced as tending more particularly *to [*550 supersede the re-issued patent number seventytwo, before described. Strong doubts are entertained whether any of the patents given in evidence by the respondents as superseding the particular patent of the complainants, involved in this issue, are of a character to have that effect, even if the inventions which they purport to secure were of prior date, but it is not absolutely necessary to decide that point, except as to one of the exhibits, as the court is of the opinion that none of the others antedate the invention secured in that patent. Conclusions are all that will be useful on this branch of the case, especially as the question is one of fact dependent upon the proofs, which are somewhat conflicting, and where a full analysis of the evidence would hardly be practicable, as it would extend the Such a change in an old machine may consist merely of a new and useful combination of the several parts of which the old machine is composed, or it may consist of a material alteration or modification of one or more of the several devices which entered into its construction, and whether it be the one or the other, if the change of construction and opera-opinion to an unreasonable length. tion actually adapts the machine to a new and Proofs entirely satisfactory to the court are exhibited by the complainants showing that | where it remained for some time; that it was their invention, as described in the patent in then removed to the new shop of the maker, question, was perfected early in the summer of where it remained until it was taken to piece 1849, as a material part of a harvesting ma- and broken up by his order, and never restored chine, and that the same was reduced to practill long subsequent to the complainants' patent. tice as an operative machine during the harvesting season of that year. Hussey, from 1839, or earlier, to the time of his death, in the summer of 1860, was much engaged in the manufacture of reaping machines of various kinds. Most of his machines, how ever, were constructed without any reel and with square platforms, so as to drop the cut grain at the rear of the platform, differing so widely from the patented machine of the complainants as to require no argument to show that they afford no support to the present defense. Other machines were constructed by him with a straight guide board on the platform, which was adjustable within certain limits, and the apparatus was, doubtless, capable, to a limited extent, of causing the cut grain to be moved sufficiently out of the path of the machine to give room for a single team. Evidence to show that the invention of the complainants is embodied in those machines is entirely wanting, and it is quite clear that if any such had been introduced it could not have been credited, as the differences between them 551*] are too *palpable and material to be overcome by parol evidence. Machines were also made by him with two platforms, or with a platform in two parts, the one being attached to the rear of the other, but it required two men to do the work which, with the complainants' machine, is easily and much better accomplished by one, which is certainly all the explanation which need be given of those machines in the present case. Apart from these he also made one experimental machine, with a square platform, to which was bolted an angular addition, giving the whole, when the addition was attached, an angular form. Examined when the addition is bolted to the main platform, irrespective of the other ingredients of the combination, it approaches much nearer to the invention of the complainants than any of the other exhibits introduced in evidence by the respondents. Conceding all that, still it would not be difficult to show that the two are substantially different in several respects; but it is unnecessary to enter that field of inquiry, as the proofs are entirely satisfactory to the court, that the machine, as constructed, was merely an experiment, and that it was never reduced to practice as an operative machine. Undoubtedly, it was built in the autumn of 1848, subsequent to the close of the harvest season; but the respondents' testimony shows that it was not used for cutting grain during that harvesting season. Some obscurity surrounds its early history, nor is it of much importance that it should be better known. It appears that it was sent to the railroad depot to be transported to some other place for trial; but there is no positive evidence that it was ever forwarded or used, or that it was capable of any beneficial use. Where it was transported, if at all, from the depot does not appear; but it does appear that it was returned the next year to the shop of the naker, and that it was set against the wall by the side of the street, in front of the shop, *Original and first inventors are en-[*552 titled to the benefit of their inventions if they reduce the same to practice, and seasonably comply with the requirements of the patent law in procuring letters patent for the protection of their exclusive rights. Crude and imperfect experiments are not sufficient to confer a right to a patent; but, in order constitute an invention, the party must have proceeded so far as to have reduced his idea to practice, and embodied it in some distinct form. Desertion of an invention consisting of a machine, never patented, may be proved by showing that the inventor, after he had constructed it, and before he had reduced it to practice, broke it up as something requiring more thought and experiment, and laid the parts aside as incomplete, provided it appears that those acts were done without any definite intention of resuming his experiments, and of restoring the machine with a view to apply for letters patent. Johnson v. Root, 2 Cliff. 123; Gayler v. Wilder, 10 How. 498; Parkhurst v. Kinsman, 1 Blatchf. 494; White v. Allen, 2 Cliff. 230. He is the first inventor, in the sense of the patent law, and entitled to a patent for his invention, who first perfected and adapted the same to use, and it is well settled that until the invention is so perfected and adapted to use it is not patentable under the patent laws. Washburn v. Gould, 3 Story, 122; Cahoon v. Ring, 1 Cliff. 612. Argument is hardly necessary to show that nothing else introduced in evidence by the respondents as having been constructed by that inventor is of a character to interfere, in any substantial respect, with the novelty of the invention held by the complainants, as the weight of the evidence plainly tends to disprove the allegations of the answer, and the inferences to be drawn from a comparison of the exhibits would establish the opposite theory even if the other proofs were less decisive to that effect. Prior invention by Thomas D. Burrall is the next defense set up by the respondents to the particular patent under consideration. They attempt to show that he constructed a harvesting machine having a square [*553 platform, to which he attached an apron, quadrant formed, which would deliver the cut grain, heads foremost, at the side of the machine and out of the way of the team in cutting the next swath. Concede the fact that the machine, together with the circular apron, was constructed by the person named as alleged, and that the machine in that form antedates the invention held by the complainants, still the court is of the opinion that it is not of a character to defeat the complainants' patent, as it had no reel, was not a self raker in any view of the case, and consisted beyond doubt of a substantially different combination. Compared with that, the invention described in the complainants' patent is both new and useful, and is plainly sufficient to support a patent as a new arrangement. Suppose it to be otherwise, still the conclu |