dissented. At this late period, when the patentee is in his grave, and his patent has expired a natural death, we are called on to say, whether his patent ever had a legal existence, and it may seem not very important to the representatives of the patentee what may be the decision of this Court, But understanding that many other actions are pending for a violation of this part of the patent right, and that infractions have taken place for w.hich actions may yet be commenced, and believing *436that the decision we are about to make will have a very extensive, if not a disastrous bearing on many other patents for improvements, and will in fact amount to a repeal of many of them, I have though proper to assign my reasons for dissenting from the opinion just delivered.
in doing this, my remarks will be confined principally to the charge of the Court, so far as it applies to the claim of Evans for an improvement on a Hopperboy.
I was much struck with the argument of the plaint-tiffs counsel in favour of the patent being for an original invention, and not for an improvement; nor would it in my opinion be a forced construction, to regard it as a. patent for a combination of machines to produce Certain results, and not for any of the machines, nor the different parts of which the whole is composed.
But considering it as a patent for an improvement of. a Hopperboy, in which light it had been regarded, as well by the Circuit as by this Court, when this cause was here before, I proceed to examine the charge, so far as it relates to this part of the subject.
The Court, afteV stating in what particulars the plaintiff’s counsel contended. that his improvement consists, which is unnecessary to repeat here, proceeds—
The plaintiff has laid before you strong evidence to prove that his Hopperboy is a more useful machine than the one which is alleged to have been previously discovered and in use. If, then, you are satisfied of this facti the point of law which has been *437raised by the defendant’s counsel remains to be considered, which is, that the plaintiff’s patent for an improvement is void because the nature and extent of his improvement is not stated in the specification.
“ The patent is for an improved Hopperboy, as described in the specification, which is referred to and made part of the patent. How does the specification express in what his improvement consists ? It states all and each of the parts of the entire machine, its use and mode of operating; and claims, as his invention, the peculiar properties or principles of the machine, viz. the spreading, turning, and gathering the meal, and the raising and lowering of its arms by its motion, to accommodate itself to the meal under it. But does this description designate the improvement, or in what it consists ? Where shall we find the original Hopperboy described, either as to its construction, operation, or use, or by reference to any thing by which a knowledge of it may be obtained ? Where are the improvements on such originals stated ? The undoubted truth is, that the specification communicates no information whatever upon any of these points.” After stfme farther reasoning on the subject, and showing that the plaintiff’s case is not excepted from the general rule of law, by the act which was passed for his relief, the Court declares.that for this imperfection or omission in the specification, the u plaintiff is not entitled to recover for an alleged infringement of his patent for the •improvement on the Hopperboy.” This was equivalent to saying that for this defect in the specification, •the patent for the improved Hopperboy was void, and, *438of course, that no action at all, whatever might be the state of the evidence, could be maintained for the use of it. It left nothing, as it . regarded the improved Hopperboy, for the jury to decide. Such is the charge, and it is delivered in terms too plain to be misunderstood.
The objections to it are now to be considered, in doing this it will be shown,
1st. That the specification is not defective, and that although it does not discriminate in what particulars the machine in question does differ from other Hopperboys in use, yet, if from the whole of the description taken together, the machine is specified so minutely, and so accurately, as to be directly and easily distinguished from all other Hopperboys'antecedently known-, every thing has been done which the law requires, and the patent is good.-
2d. That if the specification be vicious in the points mentioned, the patent ought not to be considered as absolutely void ; but it is enough, and the public interest is sufficiently guarded, if care be taken that it shall not be extended to create a monopoly in any other machine, which may or may not be mentioned in the patent, which was previously known or in use. And,
3d. That if a patent must be set aside for such defect in the specification, it should be left to the jury, on the evidence before them, to decide whether the improvement'patcnted be not set forth with all necessary precision.
1. I have said the specification is not defective.
In determining this question, it would seem but *439natural and just that the validity of a patent granted under a particular act of Congress, should be tested by the terms there used, and by the decisions of our own Courts, so far as they are of authority, and that we should be extremely cautious in adopting the rules which have been introduced into other countries, and under laws not in every respect like our own, however respectable the tribunals may be which may have prescribed those rules ; and this the more especially, as most of the decisions in England, which are generally cited, and seem to. have been implicitly followed in this country, are of a date long subsequent to the revolution, and many of them posterior to .the passage of the patent laws in this country, and which could not therefore have been in the contemplation of Congress at the time. Besides, there is somewhat of hardship in constantly applying to a patentee in this country, adjudications made on a British act of Parliament very unlike our own, and with which decisions he has no means of becoming acquainted until long after a knowledge of fhem can be of any service. Already have we extended to patents for improvements on old machines, several recent decisions in England, although it was long doubted in that country, and as late as the year 1776, whether by the^ct of the 21 James Í. c 3. there could be a patent for an addition only. When the English Courts decided in favour of such patents, they also made rules for their construction, as cases arose; there being no direct provisions in the statute on the subject. As we have provided by law, not only for the security of inventions entirely new, but also for the *440protection of those who may discover any new and useful improvement on any art, machine, &c. not known or used before, and have prescribed the terms on which patents under it may be obtained, it would seem, if all those terms are complied with, and the invention be really new and useful, that no Court can have a right to add any other terms, or to require of a patentee any thing more than what the law has enjoined on him. Let us how try the patent before us by this rule :--The.act of the 21st February, 1793,c. II. after stating in what cases letters patent for inventions may issue, and how they are to be obtained, requires, inter alia, that the inventor, before he receivés his patent, shall take a certain oath, and shall deliver a written description of his invention, and of the manner of using the same, in such full, clear, and exact terms, as to distinguish the same from all other things before known, and to enable any person skilled in the art or science of which it is a branch, or with which it is most nearly connected, to make and use the same. And in the case of a machine, he shall fully explain the principle, and the several modes in which he has contemplated the application of that principle, or character by which it may be distinguished from other inventions ; and he is to accompany the whole with drawings and written references, where the nature of the case admits of it; and a model of his machine, if required by the Secretary of State, is also to be delivered.
In the present case, the patent is for an improved Hopperboy; a particular description of which, and its uses, will be found in 3 Wheat. Rep. 466. It is *441not pretended that this machine, if made in conformity with the description giverr by Mr. Evans, could not in fact be distinguished from every thing else before known, when brought into comparison with it, nor that a skilful person, from its description, would not be able to make one like it; W'hieh would seem.to satisfy every requisition of the lawr. But the defendant’s counsel say this is not enough. It should not only in its organization and aggregate be different from every thing else,- but every respect in which it differs in its construction Or operation from other machines. should be minutely stated in the specification; or, in other wmrds, that other machines heretofore used for similar purposes, should be either described or referred to therein, and the differences between the patented machines and those in former use, be carefully designated.
The answer to this is, that the law does not require it — that it is impracticable, and would be of no use.
We have seen already that the law prescribes no precise form of specification, which would have been impracticable, and imposes no obligation fo describe, in any particular mode, the machine in question. Not a w'ord is said as to showing in what particulars the improvement patented differs from all other machines for the same purpose then in úse. If, on the whole description taken together, the machine of the plaintiff can be distinguished from other machines wrhen compared with his, the words and the objects of the law are satisfied. The law appears to have nothing else in view, in requiring a specification, than the instruc*442tion of the public ;■ that is, to guard them against a violation of the patented improvement, and to enable them, when the letters patent expire, from the specification filed, to make a machine similar to the one which had befen patented. The only inquiry, therefore, ought to be, -whether this obvious intention of the legislature has been answered by the particular specification which may be the subject of litigation ; and if enough appears, either to prevent a person from encroaching on the right of the patentee, or to enable a skilful person to make a machine which shall not only resemble the one patented, but produce the like effect', more ought not to be required. Whether these ends be attained by a particular description of every part- of the improved machine, or by describing in what respect it differs from other machines, can make no difference. The information to the public is as valuable and intelligible, if not more so, in the former case, than in the latter. If it be, taken altogether, an improved machine, for the purpose of producing certain results, and so described that it may be distinguished from other machines, and that others may be made on the same model, it is a literal compliance with all that the law requires. If the different parts of the machine, and their combination, or connexion, be accurately described, or intelligibly set forth, why should it not be supported, although no reference be made to other machines dissimilar in construction, and which, although applied for the same purpose, are inferior in the beneficial results produced by them. To the objection, that it does not precisely appear in *443what the patent Hopperboy differs from those, antecedently in use, the answer is, and it ought to be conclusive, that the patentee does .not metfii to abridge or restrain the public from using those or any other machines, so that they differ, from the one described by him; and that any mechanic, on having his specification before him, Can. avoid an interference with his invention. To confine our examination to the only Hopperboy which w$as produced on this trial, and which was called Stouffer’s Hopperboy, and of which a model has been exhibited to the Court, together with a model of Evans’ improved Hopperboy, can a doubt be entertained for. an instant, that they are very dissimilar, and thar any mechanic would not, in a moment, point out the- distinctions between them, either from the specification or the model — or that he would not be able to make a Stouifer Hopperboy, or the improved Hopperboy of Evans, as he might be directed ; and in ii,ke manner he would be able, when brought together, to discriminate between any other Hopperboy artd that of Evans, provided they were different, so that- those who were desirous of having a Hopperboy, on an old construction, and of not interfering with the rights of Mr. Evans, would labour.under no difficulty whatever. But inasmuch as Evans himself has not discriminated or exhibited in his specification all the points of difference between his and other Hopper-boys, it is supposed that his patent is for some Hopperboy already in use, as well as for his improvement thereon. The very terms of his specification precluded every supposition of that kind. If there *444wore a thousand of those machines, on different constructions, in use before the date of his patent, he leaves to the public the undisturbed enjoyment of them. He meddles not, nor does he pretend to interfere with any of them, until they make or use one constructed, in all its parts, upon his model. That form, and that form alone, he claims as his invention or improvement. It would not have been difficult, even from British authorities, to show that this specification was sufficient; but I prefer recurring to our own law as the only proper criterion of the validity or invalidity of the specification in question. My opinion is, that it has all the certainty which is required bylaw.
Such a specification as is required by the Circuit Court, is not only not prescribed by law, but, to me, it appears to be one extremely difficult, if not impracticable.
If the inventor ot an improved Hopperboy is to discriminate, in his specification, between his improvements and any particular Hopperboy, which may be produced on that trial, and is to be non-suited for not having done, so, however correct, and distinguishing it may be in every other respect, he must do the like as to all other Hopperboys ; and if he must describe any, he must describe all others with which he may be acquainted ; and, aftei all, some one may be introduced at the trial, of which he had never heard, or which he had never seen; and inasmuch as he had not stated in what respects it was improved by his machine, although this would immediately be seen on inspection, he must not *445only fail of recovering damages for a manifest violation of his right, but must have his patent declared void by the Court, without a trial by jury, and be deprived of the fruits of a most valuable improvement, not because he was not the bona fide inventor - — not because he had not described his improvement with sufficient certainty, according to the act of Congress — but because something more was required of him, of which he had no means of information. The only Hopperboy which made its appearance on this trial, except the plaintiff’s, was that, known by the name of the Stouffer Hopperboy; but non constat, that there may not have been a hundred different kinds in use, and some entirely unknown to the plaintiff. If he could have described them all, which would not have been an easy task, and stated in what particulars his Hopperboy differed from them all, his specification would have extended to an immoderate length, and after all have been less intelligible and satisfactory than a full description, such as is given here, of all the parts of which his consisted, and of the manner in which they are pot together. There may be cases in which an improvement may be so simple as to describe it at once by reference to the thing or machine improved, as in the case of an improvement of this kind on a common watch. Cut even in the case of a watch, if the improvement pervades the whole machine, it would be a compliance with the terms of the law, if the patentee described every part of his improved watch, with its principle, without discriminating particularly in what respect his different wheels, &c. varied from all other watch" *446esthen in use. Many patents have been obtained for improvements on stoves, locks, &c.; but has.it ever been required of the patentee, in such cases, not only to describe in w hat manner his stove or lock is constructed,, and the benefits resulting from such construction, but to point out every particular in which they differ from those already in use ? This, to say the least, Would be a work of great labour, and of little or no use to the public, who would be at liberty to use a stove or lock of any construction, not interfering with the one described in the specification of the patentee.
. A tew observations will show that such a description as the defendant’s counsel contend for, would be of no greater use than the one which Mr. Evans has adopted. After all the pains to discriminate had been taken, the question would still* recur, how is the improved Hopperboy to be constructed ? and if, from the specification, that , could not be ascertained, then, and then only, ought it to be pronounced defective. But if, from the description, the improved Hopperboy could be made by' a skillful mechanic, then the public is informed, not only of what has been patented j but of what still remains common as before, and if an action be brought for a violation of the patented right, and it should appear that the Hopperboy used is not of such construction, the plaintiff must fail in'.his suit. It cannot be said, with any justice, that if the discrimination be ndt made, the patent includes not only the improvement, but the old machine on which the improvement is engraft*447ed. The old machine still femains public property ; may be used by every one ; nor can any person be considered as infringing on the patent right, until he adds to the machine already in use the improvements of the patentee, or, in other words, until he makes a machine resembling, in all its parts, the one which is described in the specification-
2d. But if the specification be, defective in the points which have been mentioned, is the patent therefore necessarily void ? This is a question of vital importance to every patentee.
I am aware that it has been said in England, that the patent must not be more extensive than the invention ; therefore, if the invention consists in an im - pro,vement only, and the patent is for the whole machine, it is void. But I am not aware that it fias ever been decided there that when a patent is for an “improved machine,” and is, taken out only for the machine thus improved, and net for the machine as before used, that such patent is void. But whatever may have been some of the late decisions in that country, I prefer, and think it the better course, to consider this question also under our own act, w hich, in this respect} is different from the English statute, and will therefore afford us more light, and be a safer guide than either that statute or the judgment on it. In what part, then, of our act, may it be asked, is an authority given to the Federal Courts to declare a patent void for a defective specification, however innocently made, and whicfi in its consequences can injure no one ? I state the question in this way, not because I think it necessary to show that if injurious conse* *448quences might flow from an imperfect specification, a patent must necessarily be declared void, but because 1 think it must be admitted that there is no evidence whatever in this cause, to induce any one to believe that Mr. Evans either intended to take, or that he did receive a patent for any thing beyond his invention, which was the Jiioppcrboy in the improved condition in which he describes it. To declare a patent for a highly useful improvement absolutely void, merely.lor a defective specification, if this be one$ is a very high penalty, and should not be lightly inflicted, unless rendered absolutely necessary by law ;tne more .especially, as without recurring to .so harsh a measure;, a Court and jury will always be able to confine a remedy, on the patent to violations of the improvement actually secured, and if the patentee should be so’ foolish, or ill-adyised, .as to attempt to bring within its reach the machine in its unimproved state, or any other machine before common, he would do it, not only with no prospect of success, but with the certainty ot a defeat, attended with a very heavy expense. As long, therefore,,as he could maintain no action, but for his improvement, it is not perceived why he should be visited with so heavy a denunciation as the forfeiture of hiá improvement, merely because, by some construction of his specification, which might after all be a mistaken one, he had included in his invention, something of ever so trifling, a nature, which was already known. But if such be the law, and such tile frail tenure on which these rights are held, however hard it may apply in particular cases, it must have its course. But *449I cannot think it our duty, or that we have any right to pronounce a patent void on this account; but that this important office is exclusively confided to a jury. Whether we have this right or not, will now be examined. If such summary authority were intended to have been conferred on the Federal Courts, the patent law ought to have been, and would have been, explicit. This is so far from being the case, that in the patent law, a provision, but of a different kind, is inserted on this very subject, which is not the case in the statute of James. It .was foreseen, that it must sometimes happen, either from the imperfection of language, or, the ignorance of a patentee, that defective specifications would be made; it was also foreseen, that an imperfect specification might be made from design, and with a view of deceiving the public. We accordingly find it provided by law, that among other matters which the defendant may rely on in an action for infringing a patent right, is, “ that the specification filed does not contain the whole truth relative to his discovery, or that it contains more than is necessary to produce the described effect, which concealment, or addition, must fully appear to have been made for the purpose of deceiving the public.” If judgment is rendered for the defendant on this ground, the patent is to be declared void. This section applies as well to patents for an improvement on an existing machine, as for an invention entirely new; and was intended to protect the patent in either case against an avoidance for an imperfect and innocent specification of the invention patented. If, therefore, the defect which is alleged, *450really exist in the, specification of the patented improvement, the Court is not authorized, on its mere inspection, to declare it imperfect, and the patent, on that account, void. Both questions are clearly questions of fact, and are so treated by the legislature. The party has a right to insist with the jury, not only that his specification is perfect, but that if it be otherwise, no deception was intended on the public; and on either ground, they may find a verdict in- his favour. So if, on the allegation, that the thing secured by patent was not originally discovered by the patentee, a verdict passes against the plaintiff, he loses his patent. In like manner, in this case, if it had .appeared that the “ improved Hopperboy,” which was the thing secured by patent,, had not been originally discovered by Mr. Evans,. and a verdict had passed against him on that ground, there would have been an end of his patent. From the tenth section, also, an argument.may be drawn against the right of a Court to declare a patent void, on mere inspection, for redundancy or deficiency in a specification. This section provides a mode of proceeding before the District Court, where there may be reason to believe a patent was obtained surreptitiously, or upon false suggestions; and if, on such proceeding, it shall appear that the patentee was not the true inventor, judgment shall be rendered by such Court for a repeal of the patent.. This is the only case in which a power is conferred on a Court, to vacate a patent, without the intervention of a jury. If a proceeding, of this kind had been instituted before the proper tribunal against Mr. Evans, the Court would *451have examined witnesses, and have formed its opinion on their testimony ; and it is not clear that even in this case a jury might not have been called in. This section bas been taken notice of, to show that it could never have been the intention of the legislature, that a patent should be avoided, on any account whatever, on the-opinion of the Court alone, without some examination other than that of the specification, whatever might be its excess, or poverty of description. If it had been intended to vest so important a power in the Court, it would not have been left to mere implication, but would have been conferred in terms admitting of no doubt. My opinion, therefore, on this part of the charge is, that the Court erred in taking upon itself to pronounce the patent void, even if the specification had been defective, or imperfect, in not particularly describing what the improvements of the patentee were; this be’ing a power expressly delegated to a jury, who,-under all the circumstances of the case, are to decide both questions of fact; that is, whether the specification be deficient, or superfluous, and the intention with which it was made so. I repeat once more, that whatever may have been the decisions in England, which are not admitted to be contrary to the view which has here been taken of the subject, they are not of authority, and are upon an act so very different in its structure from our own, as to afford little or no useful information on the subject. One great and important difference in the, two laws is — -that the statute of James I. has not prescribed a mode in which a patent for a vicious specification is to be set aside. *452The patent is granted on condition that a specification be enrolled.
I give no. opinion on the questions which arise from the admission of certain witnesses, who were supposed to be disqualified, on the score of being interested ; for if the patent for the Hopperboy be void, for a defect in its specification, and that question is not to be referred to the jury, and such I understand to be the opinion of four of the judges, it is very unimportant, whether any error was committed in this respect by the Court before which the cause was tried ; as a verdict must ever be rendered against the representatives of the patentee, on this ground, whatever may be the state of the evidence.
Mr. Justice Johnson, and Mr. Justice Duvall, also dissented.Judgment affirmed with costs.