DALLAS, Circuit Judge.

This is an appeal from a decree dismissing a bill for alleged infringement of patent No. 253,506, for an improvement in cash registering apparatus, granted to Michael Campbell, and dated February 14, 1882. The only claim involved is:

“(3) In a cash registering apparatus, a series of keys to designate certain amounts, combined with the drawer, the drawer holder, D, mediately connected with said keys, and the spring to throw the drawer open when released by the drawer bolder, substantially as described.”

The defenses are that this claim is invalid, and that, even if valid, it is not infringed. It is insisted that it discloses no patentable invention whatever, but that, if it- should be sustained, and as for a combination, tbe appellee’s machine would not he an infringement, because it not only does not contain any of tbe specific devices of the appellants’ apparatus, but also does not employ the combination al*369leged. The appellants, oil tlie o1 her hand, admit that all the specific devices were old, singly and in other combina Lions, but assert that what Campbell invented and claimed is a combination, and nothing else. Accordingly, their counsel contend that the claim in question is valid, as disclosing a patentable invention of a new and useful combination, and that the appellee’s machine is an infringement, not because of any real or supposed identity or equivalence of elements, bub because it accomplished the, same result as is accomplished by the Campbell machine, by substantially the same mode of operation. We have, then, no issue as to novelty or infringement of details, and therefore the only questions to be considered are: First. Is the claim for a combination, supported by invention? Second. Has the appellee infringed?

3. The claim is, in terms, foi mechanism "combined with” other mechanism. It is true that certain particular mechanism is mentioned, but it does nob necessarily result that the patentee intended to limit the claim to any special devices, or that the law will so restrict It. The question is one of construction; and as we are of opinion, upon grounds to he hereafter stated, that Campbell's invention was a primary one, it follows that the language of this claim should be as liberally interpreted as its fair import will allow, to the end that his conception shall be justly protected to its true extent, and in its broad and actual scope. The invention, says the specification, "reíales to -a cash registering apparatus to be employed in connection with a cash drawer,” and (he claim is for (in such apparatus) a series of keys to designate different amounts, combined with a drawer for receiving cash; a drawer holder, for holding the drawer closed against the tension of the spring, (presently mentioned;) a mediate connection (of some kind, not designated) between the series of keys and the drawer holder, by which the latter will be disengaged from the drawer upon the operation oí any one of the keys; and a spring to throw the drawer open when so disengaged. By this contrivance the cash drawer, which when closed is always locked, is, by the operation of any one of the keys of the series, thrown open by the spring; and none of the devices by which this object is accomplished, so far as they are designated in the third claim, were new. The series of keys, the cash drawer, and the spring were unquestionably old; and the drawer holder is but a pivot lever, differing from other levers of the same class in nothing but in form, and in the use to which the patentee applied ib. Of any particular mechanism of mediate connection, nothing need he said at this point. Hone is specifically mentioned in the claim with which, alone, we are concerned; and for the present purpose ib may be taken for granted that none which was new was contemplated. It is clear, then, that so to construe this claim as to (online it to specific details would be to invalidate it for lack of novelty: A consequence which certainly ought not to be accepted when, according to the natural and ordinary meaning of its language, it plainly appeal's to be a claim for a new combination of old devices, — a well-known series of keys combined with the other familiar mechanism mentioned, and mediately connected, in some way not mentioned, with the drawer holder included *370in that mechanism. It cannot be restricted to all or any of the devices used in the mediate connection between the series of keys and the drawer holder, not only because they are uot even specified in the third claim, but also because they are expressly claimed in the second claim, which is:

“(2) In a cash registering apparatus, a series of keys to designate certain amounts, a pawl-carrying Dar, c, and a series of toggle levers, x, intermediate between each key and the said pawl-carrying bar, the toggle lever, b, actuated by the bar, c, combined with the drawer holder, D, and drawer, 0, substantially as described.”

There is nothing upon this record which would warrant us in attributing to the patentee the folly of having presented, and to the patent office the improvidence of having allowed, two claims for the same thing. The distinction between them must be maintained, that both may be given effect.

The court, whose decree is the subject of this appeal, expressed no independent opinion, but merely followed the decision of the circuit court for the district of Massachusetts in a suit in which the same claim had been in controversy. National Cash Register Co. v. Boston Cash Indicator & Recorder Co., 45 Fed. Rep. 481-485. The course pursued in this regard was in conformity with the rule, well established in this circuit, to follow, unless under extraordinary circumstances, a prior judgment of any other of the circuit courts of the United States, wherever the patent, the question, and the evidence are the same in both suits. We do not question the propriety of this practice, as it has heretofore prevailed; but it cannot be extended to this comd. The decisions of the several circuit courts, whenever pertinent, will be attentively considered by this tribunal; but because they are subject to appeal, and for other manifest reasons, it is not admissible for a court of review to accord them controlling effect. Accordingly, we have in this instance carefully examined the opinion of the learned circuit judge of the first circuit ; but, though regarding it with sincere respect, we find ourselves in-able to concur in it. This claim, as we read it, is, distinctly, exclusively, and broadly, for a new combination; and we know of no authority or principle of law which, so reading it, would warrant us in converting it, by construction, into a claim for details merely.

Thus far we have assumed that the actual invention was of a new and useful combination, and also (perhaps without necessity) that it was a primary one. We will now state the reasons by which these- assumptions are supported. Whether or not the “connecting mechanism” between the drawer holder and the keys was new with Campbell is, in our opinion, apart from the question. That mechanism, or any part of it, was not, as we have shown, covered by the claim in controversy. The complainants’ bill was not founded upon it; and this court is not called upon to deal with it, buü solely with an alleged combination, which it is asserted, but denied, was invented by Campbell. Directing our investigation, therefore, to this distinct issue, we have, upon full examination of the proofs,, become entirely satisfied that Campbell was in fact the original and first in*371ventor of the combination claimed in his third claim, it is unnecessary to refer in detail to the several exhibits which were introduced to show' the prior state of the art, or to enter upon a discussion of the testimony. It is enough to say that, upon all the evidence, we do not doubt that Campbell was the first person who combined a series of keys with any other mechanism whatever, so as to attain the object; which he proposed and accomplished. It nowhere appears that a, combina lion of a series of keys with a drawer holder and other mechanism had ever before been conceived, by means whereof each key of the series, rvlien and as operated, would or could unlock a drawer in a cash registering apparatus, and permit a spring to open it. This Campbell effected, not by new mechanism, but by a new' combination, and in doing this he made a patentable invention.

We have not overlooked the suggestion of appellee’s counsel that . Campbell’s conception and arrangement were merely of an aggregation of known elements, not amounting to a true combination, and that, therefore, he was not entitled to a patent for anything. This suggestion is based upon ihe allegation that each of the elements associated by Campbell does not; qualify every other of them; but this is true only in the sense that each does not modify or change the characteristic mode of action, or method of operation, of the others. In doing its appointed share towards effecting the single result achieved by the co-operation of all, each element acts, of course, according to the law of its own being; hut, though of necessity so acting, it is still, none the less, combined with tlie others, and does “qualify” each and all of them, (not their distinctive methods of operation,) in the sense that each is, by the co-operation of the others, capacitated to contribute, by acting in its own peculiar w’ay, to the common end, ■which, without the co-opera I ion of each and every other of the co-ordinated elements, it w'ould he powerless to accomplish, or advance. Some of the language used by Mr. Justice Matthews in delivering the opinion of the supreme court, in Pickering v. McCullough, 104 U. S. 310, has been jiressod upon our attention, as indicating, it is claimed, that in a patentable combination of old elements all the constituents must so enter into it that each changes the mode of action of every other, and that each element must not merely perform its own part in the combination, hut must; also, in some way, he directly and immediately concerned in the performance of their respective parts-by every other of the elements. No such doctrine as is thus claimed to he deducidle from the opinion in Pickering v. McCullough appears to have boon essential to the judgment in that case, nor do we think it neceisary to attribute to the particular language referred to (104 U. S. 318) the meaning ascribed to it by counsel. If, instead of an extract, the whole opinion he read, in connection with the authorities which are cited in it, it may be readily perceived that the substance of the doctrine intended to be affirmed is that a combination, to he. patenta,hie, must produce a new and useful result, as the product of the combination, and not amere aggregate of several results, each the complete result of one of the combined elements. There must he a new result produced by their union. That *372Campbell’s invention was of a combination, as thus defined, we entertain no doubt; and that Mr. Justice Matthews should be understood as holding that ho combination is patentable which does not fulfill the requirement which appellee’s counsel insists is requisite, we cannot suppose. If it were essential to a valid patent for any combination whatever that the mode of action of every element included in the combination should be changed by each of the others, it would have been impossible to sustain several combination patents which have in fact been upheld, as, indeed, it would be difficult-to conceive of any mechanical combination which would be both possible and patentable. A screw or a- lever can act only in one way, yet a screw and a lever may so act in combination as to produce, in consequence of their combination, a single, new, and useful result. Moreover, there is no intimation in the opinion in Pickering v. McCullough of a purpose to overrule the earlier decisions with which (upon the view taken of it by counsel) it would appear to conflict, nor .has it in later cases (which, of course, are to be followed) prevented the supreme court from declaring the law of this subject in accordance with our understanding of it. Blake v. Robertson, 94 U. S. 728; Parks v. Booth, 102 U. S. 96; Loom Co. v. Higgins, 105 U. S. 580; Clough v. Barker, 106 U. S. 166, 1 Sup. Ct. Rep. 188; Lake Shore & M. S. Ry. Co. v. National Car Brake Shoe Co., 110 U. S. 229, 4 Sup. Ct. Rep. 33; Lock Co. v. Sargent, 117 U. S. 536, 6 Sup. Ct. Rep. 934.

Campbell’s invention was a primary one. The proofs abund-uilv establish that he was the first person who succeeded in effecting, in any manner or form whatever, the opening of an automatically locked cash drawer, in a cash registering apparatus, upon the operation of any one or other of the keys of its series. In doing this he did not merely improve upon something which had been done before. What he produced was absolutely and entirely new. The result which he achieved was a distinct and single one, which had not, by any means, been previously attained. He entered upon barren territory in the domain of invention, and was the first to occupy and appropriate it. He was a pioneer. Machine Co. v. Lancaster, 129 U. S. 263, 273, 9 Sup. Ct. Rep. 299. That Campbell’s invention was useful, we are also fully persuaded. The evidence of this is so complete as not to require detailed discussion. Indeed, the ocular proof of its practical utility, manifested by the operation of the apparatus in our presence, would of itself be sufficient to require us to conclude that it does not lack this essential of patentability.

2. But little need be added with especial reference to the matter of infringement. In National Cash Registering Co. v. Boston Cash Indicator & Recorder Co., supra, it was held that the mechanism specifically designated in the third claim was old, but that the mechanism of mediate connection, which was not designated, was new, and that there was no infringement of the patent, because the defendants used a connecting mechanism -which differed from that used by the plaintiffs. As we, however, have been constrained to view this claim as for a combination, the question of infringement must necessarily be considered by us as related to a subject quite *373distinct from that to which the same question was directed in the decision of the case to which we have referred. The correct inquiry, from our point of view, is not whether this appellee uses, in its mechanism of mediate connection, the same devices which are used by the appellants, or equivalents thereof, but whether the mediate connection employed by the appellee is not; itself an equivalent of the mediate connection of the Campbell combination. It may be conceded that there are marked differences in the details by which this connection is made, and its purpose accomplished, in the one apparatus and in the other; hut the manifestly well-founded expert testimony is that “a mediate connection,” not the details thereof, is included among the elements of the Campbell machine. This element, as well as all others of the patented invention, are found in the appellee’s apparatus. We a ttacli no importance to the fact that in the appellants’ machine the drawer is released upon downward pressure of the key, while in tha t of the appellee it is released as the finger leaves the key to which the pressure is applied. In both, the drawer is opened by what is substantially one and the same act,— the operation of a key of the ser ies. Though some of the corresponding parts of the machinery are not the same, and, separately considered, could not be regarded as identical or conflicting, yet, having the same purpose in ¡he combination, and effecting’ that purpose in substantially the same manner, they are the equivalents of each other in that regard. Cochrane v. Deener, 94 U. S. 780. We are of opinion that the combination here claimed is infringed by the apparatus used by the appellees.

The decree of the circuit court is reversed, with costs, and it is ordered that, this cause be, and the same is hereby, remanded to the said circuit court for further proceedings to be there taken in. pursuance of ibis determination and judgment of This court, and in conformity with this opinion.