forfeit their title. The other stipulations in this conveyance are immaterial to the decision of the case. The defendant relied upon a notarial act from the City of New Orleans, dated in 1816, conveying the property in the same lot to one Clay, upon a contract of sale, and an act dated in 1823 from Clay, conveying the property to the defendant. In each of these the vendees acknowledge that possession of the lot had been delivered at the date of the deeds. The plaintiffs requested the court to instruct the jury that the City of New Orleans, by the Notarial Act of 1810, had transferred to Sticher and Anderson the title and the possession of the property, and that neither the title nor the possession can be presumed to be afterwards in the city, but that the city should show that the title and possession came lawfully into its hands. This request was refused by the court, and the jury was instructed that the deeds from the city to Clay of 1816, and from Clay to the defendant in 1823, were of themselves evidence of possession in the defendant and his vendor to support the plea of prescription. The court further instructed the jury, that under the written proofs and law of the case, the plea of prescription must prevail. These instructions were excepted to, and are here assigned as error. This article was designed to declare the operation of a contract for the transfer of property when embodied in a public Act as between the parties to the Act. It establishes, that the transfer is complete by the use of apt words of conveyance in such an Act, without the formality of a real delivery; that the power of control and enjoyment, transferred by a grantor in such an Act, is equivalent to a manual or physical tradition. So exactly the equivalent, that an "interfering obstacle," interposed by the grantor afterwards, may be treated as a trespass-that is, a disturbance of the possession of the grantee. This rule from the Louisiana Code, corresponding with the Code Napoleon, deviates from the rule of the Roman and feudal law, which exacted a formal delivery, to perfect the transfer of the property. *The rule is in complete harmony with[*329 the American system of conveyancing, which accomplishes the cession of property, with its incidents of possession and enjoyment, without a resort to symbolical acts, or inconvenient ceremonies, by the consent of the owner, legally authenticated. This explanation of the object of the article of the Code, will enable us to define the limits of its operation. A vendor cannot transfer a title, or a possession, which is not vested in him. He cannot, by his conveyance or admissions, affect the claims of persons whose title is adverse to his. It follows, therefore, that the delivered, and that the vendor was satisfied therewith, are not evidence of that corporeal possession, which is the foundation of a prescriptive right in a case like the present. Tropl. De Vente, secs. 36, 40; C. C. 2233, 2235; Emmerson v. Fox, 3 La. 183; Ellis v. Prevost, 19 La. 251. 328*] *The conveyance from the city to Sticher and Anderson, of 1810, was upon a resolutory condition. The contract between the parties was not dissolved of right by the non-recitals in these acts, that possession had been fulfillment of the condition, but the party complaining of the breach might have insisted upon its dissolution, with damages, or upon a specific performance. C. C. 2041, 2042. The dissolution of the contract for the nonfulfillment of the conditions, could not be inferred merely from the fact of a subsequent conveyance by the City of the same property. The title of the City to the lot passed to Sticher and Anderson by the Notarial Act of 1810, and to sustain a posterior conveyance of the City, it should have been shown, either that the first contract had been revoked, or that another title had been acquired. The court erred, therefore, in refusing the instruction requested by the plaintiffs. 2. To sustain a title by prescription to im movable property, according to either of the articles of the Civil Code, referred to in the pleas, the defendant was required to show "a public, unequivocal, continuous and uninter rupted possession," "under the title of owner." "The possessor must have held the property in fact and in right as owner," "though a civil possession would suffice, if it had been preceded by the corporeal possession." C. C. 3462, 3467, 3453; Devall v. Choppin, 15 La. 566. The court has been referred to the Civil Code (C. C. 2455) to prove that the claims of the articles of the code we have cited are fulfilled by the public acts produced by the defendants. This article is "that the law considers the tradition or delivery of immovables as always accompanying the public act which transfers the property. Every obstacle which the seller afterwards imposes, to prevent the corporeal possession of the buyer, is considered as a tres pass." 3. As a general rule the possession necessary to sustain a prescription is founded upon facts, which it is the province of a jury to ascertain. Ewing v. Burnet, 11 Pet. 41; Beverly v. Burke, 9 Ga. 440. But the "written proofs," upon which the Circuit Court felt authorized to instruct the jury that the plea of prescription must prevail, are not exhibited in the record, and this court cannot, therefore, test the accuracy of its conclusion. For the errors in the charge that we have noticed, the judgment of the Circuit Court must be reversed, and the cause remanded for further proceedings. Order. This cause came on to be heard on the transcript of the record from the Circuit Court of the United States for the Eastern District of Louisiana, and was argued by counsel; on consideration whereof, it is now here ordered and adjudged by this court, that the judgment of the said Circuit Court in this cause be, and the same is hereby reversed, with costs; and that this cause be, and the same is hereby remanded to the said Circuit Court, with directions for further proceedings to be had therein in conformity to the opinion of this court. 380*] *ROSS WINANS, Plaintiff in Error, pack,' as it is technically termed. Experience has shown, that cars on the old mode of con V. ADAM, EDWARD and TALBOT DENMEAD.struction cannot be made to carry a load greater than their own weight; but, by my improvement, I am enabled to make cars of greater durability than those heretofore made, which will transport double their weight of coal. Patent covers variation in form attaining same result-Coal cars with drop bottoms-Construction of specification. A patent was taken out for making the body of a burden railroad car of sheet iron, the upper part being cylindrical, and the lower part in the form of a frustum of a cone, the under edge of which has a flange secured upon it, to which flange a movable bottom is attached. The claim was this: "What I claim as my invention and desire to secure by letters patent, is, making the body of a car for the transportation of coal, etc., in the form of a frustum of a cone, substantially as herein described, whereby the force exerted by the weight of the load presses equally in all directions and does not tend to change the form thereof, so that every part resists its equal proportion, and by which also the lower part is so reduced as to pass down within the truck frame and between the axles, to lower the center of grav. ity of the load without diminishing the capacity of the car as described. I also claim extending the body of the car below the connecting pieces of the truck frame and the line of draught, by passing the connecting bars of the truck frame and the draught bar through the body of the car, substantially described." This patent was not for merely changing the form of a machine, but by means of such change to introduce and employ other mechanical principles or natural powers, or a new mode of operation, and thus attain a new and useful result. Hence, where, in a suit brought by the patentee against persons who had constructed octagonal and pyramidal cars, the District Judge ruled that the patent was good for conical bodies, but not for rectilinear bodies; this ruling was erroneous. The structure, the mode of operation, and the result attained, were the same in both, and the specIfication claimed in the patent covered the rectif near cars. With this explanation of the patent, it should have been left to the jury to decide the question of infringement as a question of fact. HIS case was brought up by a writ of error Tfrom the Circuit Court of the United States for the District of Maryland. It was an action brought by Ross Winans for the infringement of a patent right. The jury, under the instruction of the District Judge, the late Judge Glenn, then sitting alone, found a verdict for the defendants; and the plaintiff brought the case to this court by writ of er ror. The principle of my invention, by which I am enabled to obtain this important end, consists in making the body, or a portion thereof, conical, by which the area of the bottom is reduced, and the load exerts an equal strain on all parts, and which does not tend to change the form, but to exert an equal strain in the direction of the circle; at the same time this form presents the important advantage, by the reduced size of the lower part thereof, to extend down within the truck and between the axles, thereby lowering the center of gravity of the load." The specification then gives a detailed description of the mode of constructing the cars in question, and proceeds thus: "What I claim as my invention, and desire to secure by letters patent, is making the body of a car for the transportation of coal, etc., in the form of a frustum of a cone, substantially as herein described, whereby the force exerted by the weight of the load presses equally in all directions, and does not tend to change the form thereof, so that every part resists its equal proportion, and by which also the lower part is so reduced as to pass down within the truck frame, and between the axles, to lower the center of gravity of the load, without diminishing the capacity of the car as described." And the specification concludes with a claim for a portion of the construction, not important in this connection. structed by the plaintiff, in accordance with the From the testimony it appears that cars, conspecification, while they weighed but 5,750 lbs. weight of the load, in proportion to the weight each, carried 18,550 lbs. of coal-making the of the car, as 3.3 to 1-that the thickness of the sheet iron used in the construction of the bodies mensions of the band around the top were of was but 3.32ds of an inch, and that the dian inch by 2 inches; and it is further shown, in that the plaintiff had constructed a model car, illustration of the importance of the invention, which, weighing but 21⁄2 tons, carried, nevertheless, 91⁄2 tons of coal "in perfect safety and satde-isfactorily from Cumberland to Baltimore." The nature of the case is set forth in the explanatory statement prefixed to the argument of the counsel for the plaintiff in error. It was argued by Mr. Latrobe for the plaintiff in error, and by Mr. Campbell for the fendant in error. The proportion of the weight of the car, in this instance, to the weight of coal carried in it, was as 1 to 4 nearly. It appears further, from the testimony generally, that the cars [*332 referred to were used in the transportation of coal from the mines near Cumberland to Bal Statement and points of Plaintiff in Error. On the 26th June, 1847, Ross Winans, the plaintiff in error, obtained letters patent of the United States, for a new and useful improve-timore. ment in cars for transportation of coal, etc. The occasion for the invention thus patented, and the principle of it, are well set forth in the specification, thus: "The transportation of coal, and all other heavy articles in lumps, has been attended with 331] great injury to the cars, requiring the bodies to be constructed with great strength, to resist the outward pressure on the sides, as well as the vertical pressure on the bottom, due, not only to the weight of the mass, but the mobility of the lumps amongst each other, tending to It then appears that the defendants, "in view for a call for cars from the mining roads near Cumberland," in 1849, '50, required their draftsman, Cochrane, to get up a car that would suft their purposes; that he went to the Reading road, and "finding nothing there, returned to Baltimore, and went to the plaintiff's shops, where he saw a car nearly finished, which he examined and measured." That it first occurred to him to make a square car, but that, as this would interfere with the wheels, he made an octagonal one. Another witness proves, that the iron used in the car, thus built by the defendants, was of the same thickness as that used by the plaintiff, to wit: 3.32ds of an inch, while the band around the top was of the same thickness, to wit: 4 of an inch, and 11⁄2 inches in width. It thus appears that a patent was granted, in 1847, to Ross Winans for a car for carrying coal, whose merits may be summed up thus: that it carried more coal in proportion to its own weight than any car previously in use, and that the load, instead of distorting it, preserved it in shape, acting as a framing. These eminent advantages, which increased the available power of the locomotive engine, looking to revenue on coal as a freight, from 50 to 100 per cent. were to be attributed to the peculiar shape of the car body, consisting of a frustum of a cone, which permitted the use of iron, as thin as has been described, lessening, in proportion, the weight of the car, or the weight, the transportation of which by the locomotive gave no return in revenue; and it appears, that in view of obtaining the best results from his invention, the plaintiff, in 1849, '50, at the instance of the witness Pratt, perfected a model car for certain mining roads near Cumberland; that this model car was examined and measured by the defendant's draftsmen, to aid him in getting up coal cars for other mining companies in 1849 and 1850; and subsequently, cars of the same weight of material in the bodies, which differed from the plaintiff's in this only, that while the latter were cylindrical and conical, the others were octagonal and pyramidal-were built by the defendants, to the number of 24. Believing that the cars thus built by the defendants were built in palpable violation of his patent, the plaintiff brought the present suit. It is not necessary, in this statement, and in view of the questions arising on this appeal, to go into evidence in regard to the merely colorable difference of construction in detail. All the witnesses, on both sides, proved that the advantages which Winans proposed to obtain were substantially obtained in the defendant's cars-the plaintiff's witnesses swearing to the fact directly, and the defendant's witnesses admitting it on cross-examination; and the only testimony quoted now is that of the defendant's own and leading witness. "That the advantage of a reduced bottom of the car thus obtained, whether the car was conical or octagonal; that the strengthening of the bottom, due to the adoption of the conical form, was the same when the octagonal form was adopted or the circmar; that the circular form was the best to resist the pressure, as, for instance, in a steam boiler, and an octagonal one better than the square form; that the octagonal car was not better than the conical car; that for practical purposes, one was as good as the other; that a polygon of many sides would be equivalent to a circle; that the octagon car, practically, was as good as the conical one; and that, substantially, witness saw no difference between the two." The testimony must indeed be all one way, where the plaintiff is willing to rest his case on the defendant's own showing. In the view of the plaintiff below, there were two questions; the first for the court, being the construction of the patent; the seeond for the jury, being the substan. [*334 tial, or only colorable difference between the cars in principle and mode of operation. The plaintiff prayed the Circuit Court (His Honor, the late Judge Glenn, sitting alone) accordingly. It will be seen, by examining the record, that the main question before the jury was, whether In framing the prayer for the court's conthe cars, so built by the defendants, were sub-struction of the specification, the language of stantially the same in principle and mode of operation with the car described and claimed 333*] by the plaintiff *in his specification, and experts were examined on both sides on this point. On the part of the defendants it was contended, that the cars of the defendants were octagonal in shape, while the plaintiff's were cylindrical. the specification was adopted in describing the object of the invention; and the court were asked to say to the jury, "that what they had to look at was not simply whether, in form and circumstances, which may be more or less immaterial, that which has been done by the defendant varied from the specification of the plaintiff's patent, but to see whether, in substance and effect, the defendants, having the same object in view as that set forth in the plaintiff's specification, had, since the date thereof, constructed cars which, substantially, on the same principle and on the same mode of operation, accomplished the same result." And to give more certainty to the prayer, the plaintiff added the instruction as prayed for by him, "that to entitle the plaintiff to a verdict, it was not necessary that the body of the defendants' cars should be conical, in the exact definition of the term, provided the jury should believe that the form adopted by the defendants accomplished the same result, substantially, with that in view of the plaintiff, and upon substantially the same principle and in the same mode of operation." on the part of the plaintiff it was insisted, that this was immaterial, provided the octagonal car obtained the same useful results, through the operation of the same principles in its construction; and it was suggested, that if the original construction of the body in right lines saved the infringement, an hundred-sided polygon would be without the patent; and also, that in point of fact, even the conical car was oftener a polygon than a true curve, owing to the character of the material from which it was built; and that if, by accident, it came from the shops a true theoretical cone a day or two's use made a polygon of it; and that the immediate tendency of the load of coal, when put into an octagon car, was to bulge out its size and convert it into a conical one. All of which was urged for the purpose of showing that the question was necessarily a question as to whether the change of form was colorable or substantial-a question of fact, which it be-ster's Pat. Cases, 587. longed to the jury to determine. The language of the first part of the prayer, here quoted, was taken verbatim, nearly, from the charge of Sir N. C. Tindal to the jury in the case of Walton v. Potter & Horsfall, Web This was a case where the plaintiff's patent was for the substitution of sheets of India, ment put by the Lord Chief Baron, who led on It would be hard indeed to find a case where the court's decision, applied to the facts in this cause, more completely negatived the right, set up by the defendants, to build the cars which 335*] *they did build; for here, the taking of the leaf out of the book is not left to inference; but day and date are given for the act. To the same point is the case Huddart v. Grimshaw, also cited in the court below. Webster's Patent Cases, 95. Flere a patent had been obtained for making rope, a part of the process being the passage of the strands, while being twisted, through a tube; and it appeared that they had formerly passed through a hole in a plate. If the tube and the plate were the same, substantially, the difference being colorable only, then the patent was void, otherwise it was good; and the ques tion was left to the jury, who found for the plaintiff. To the same point is the case of Russell v. Cowley & Dixon, Webster's Patent Cases, 463. This was the case of a patent for welding iron tubes, by drawing them, at a welding heat, through a conical hole. The infringement was the passing them between rollers; and the question of colorable or substantial difference was referred to the jury. As in the case under discussion, the moment a practical, scientific man is furnished with the idea of giving to the car a shape which will, by dispensing with the framing ordinarily used, enable him to make it lighter in proportion to its load than it has ever been made before, he can multiply without end the forms in which this principle can be made to operate. He can make the car a polygon of an hundred sides, of twenty sides, or of eight sides. He can vary the angle of the cone, or pyramid, through which the coal is discharged, ad infinitum. He can make the opening at the bottom larger or smaller to please his fancy. He can avail him self or not of the advantage of lowering the ear, in position, so as to lower the center of gravity. Still the question must always be, whether, whatever the shape he adopts, he is not availing himself of the principle first suggested by the patentee; a question which, in a court of law, is at all times a question not for the court, but the jury; after the former shall have given to the specification that construction which is to govern the latter in determining whether the infringement complained of falls, substantially, in principle and mode of operation, within the plaintiff's patent. tion, the question of infringement should be left to the jury. The authorities here cited, and which were relied on in the court below, are held to sustain the prayer of the plaintiff; that, having proSo in the case of Morgan v. Seaward, Web-nounced upon the construction of the specificaster's Patent Cases, 170, which was upon Gallaway's patent for paddle wheels of steam-vessels, and where the question of infringement having arisen, the court, Alderson, B., told the jury "that the question would be, simply, whether the defendant's machine was only colorably different: that is, whether it differed merely in the substitution of mechanical equivalents for the contrivances which were resorted to by the patentee." And after referring to points of construction, the court continues: "Therefore, the two machines were alike in principle; one man was the first inventor of the principle, and the other has adopted it; and though he may have carried it into effect by substituting one mechanical equivalent for another, still you (the jury) are to look to the substance, and not the mere form, and if it is in substance an infringement, you ought to find so." The court below thought differently, however, and, rejecting the prayers of both plaintiff and defendants, instructed the jury, "That while the patent is good for what is described therein-a conical body in whole or in part, supported in any of the modes indicated for a mode of sustaining a conical body on a carriage or truck, and drawing the same, and for those principles which are due alone to conical vehi cles and not to rectilinear bodies; and it being admitted that the defendant's car was entirely rectilinear, that there was no infringement of the plaintiff's patent." See Record, pages 16, 17. Upon this instruction nothing was left for the jury but to render a verdict for the defendant. The court had not only settled the conSo too in the case of Crossley v. Beverly, grow-struction, but the infringement also. ing out of Clegg's patent for a gas meter; and referred to by Alderson, B., in the case of Jupe v. Pratt et al., Webster's Patent Cases, 144, as follows: "There never was a more instructive case than that. I remember very well the argu-struction which it gave to the specifi· [*337 The present appeal is from this decision of the late District Judge. The points of the plaintiff in error are: cation, should it be held that this construction | proper in him so to instruct them. Greenleaf limited the plaintiff to the strictly conical form. v. Birth, 9 Pet. 292. And upon this point the authority relied on is the patent itself. Mr. Justice Curtis delivered the opinion of the court: 2. That the court below erred, even suppos This is a writ of error to the Circuit Court ing that its construction of the specification of the United States for the District of Marywas correct, in excluding the inquiry whether land. The plaintiff in error brought his action the cars of the defendants were not substan-in that court for an infringement of the extially the same in principle and mode of opera-clusive right to make, use, and sell "an imtion with those of the plaintiff; admitting that provement in cars for the transportation of these last were rectilinear in their sections and coal," etc., granted to him by letters patent, not curvilinear. bearing date on the 26th day of June, 1847; and the judgment of that court being for the defendants, he has brought the record here by this writ of error. And upon this point the authorities relied on, are, Walton v. Potter, Webster's Patent Cases, 587; Huddart v. Grimshaw, Id. 95; Jupe v. Pratt, citing Crossley v. Beverly, Id. 144; Morgan v. Seaward, Id. 170; Russell v. Cowley, Id. 463; Phillips on Patents, 125-127. (Infringement.) Curtis on Patents, 263, 265, 264, 5, 268; citing, Wyeth v. Stone, 1 Story, 273; Odiorne v. Winkley, 2 Gall. 51; Gray v. James, Pet. C. C. 394; Boville v. Moore, Dav. Pat. Cas. 361. 3. That the court below erred in taking the question of fact from the jury. Upon which point the authorities already cited are relied on. Defendant's Points. The defendant in error submits that the court below was right in refusing the prayer on the other side and giving the instruction which it did. 1. As to the rejected prayer of the plaintiff. This prayer asserted the essence of the invention to consist in the conical form adopted by the patentee, and rightly so asserted, but the conclusion thence drawn was a non sequitur. It was that any other form was a violation. Had the patent claimed the application of a principle operating through the form of a cone, and more or less through other forms, and claimed the principle or mode of operation through whatever shape permitted it, there would have been some ground for the deduction. But the claim is confined to a single form, and only through and by that form to the principles which it embodies; and if, out of many forms embodying more or less perfectly the same mode of operation, the plaintiff in error has made his choice of the best, he is confined to that choice and the rejection which it involves of all other forms less felicitous. It may be admitted, without hesitation, that the substitution of mechanical or chemical equivalents, as they are called, will not affect the rights of a patentee, but the cases in which this principle holds, are where the modus operandi embraces more than a single way to reach the desired end. Where the invention consists 338*] of a principle embodied in a single form, the form is the principle and the principle the form, and there can be no violation of the principle without the use of the form. Davis v. Palmer, 2 Brockenbrough, 309. 2. As to the court's instruction. The construction of the patent was exclusivey for the judge. He construed it correctly as embracing only a curvilinear form. It necessarily followed that, as the infringements relied on consisted only in the construction of rectilinear forms. there was no evidence to go to the jury of any violation of the patent, and it was It appears, by the bill of exceptions, that the letters patent declared on were duly issued, and that their validity was not questioned; but the defendants denied that they had infringed upon the exclusive right of the plaintiff. On such a trial, two questions arise. The first is, what is the thing patented; the second, has that thing been constructed, used or sold by the defendants. The first is a question of law, to be determined by the court, construing the letters patent, and the description of the invention and specification of claim annexed to them. The second is a question of fact, to be submitted to a jury. This In this case it is alleged the court construed the specification of claim erroneously, and thereby withdrew from the jury questions which it was their province to decide. renders it necessary to examine the letters patent, and the schedule annexed to them, to see whether their construction by the Circuit Court was correct. In this, as in most patent cases, founded on alleged improvements in machines, in order to determine what is the thing patented, it is necessary to inquire, 1. What is the structure or device, described by the patentee, as embodying his invention? 2. What mode of operation is introduced and employed by this structure or device? 3. What result is attained by means of this mode of operation? *4. Does the specification of claim [339 cover the described mode of operation by which the result is attained? Without going into unnecessary details, or referring to drawings, it may be stated that the structure, described by this patent, is the body of a burden railroad car, made of sheet iron, the upper part being cylindrical, and the lower part in the form of a frustum of a cone, the under edge of which has a flange secured upon it, to which flange a movable bottom is attached. This bottom is made movable, in order to discharge the load through the aperture left by removing it. To understand the mode of operation introduced and employed by means of this form of the car body, it is only necessary to state, what appears on the face of the specification, and was testified to by experts at the trial as correct, that, by reason of the circular form of the car body, the pressure of the load outwards was equal in every direction, and thus the load supported itself in a great degree; that, by making the lower part conical, this principle of action operated throughout the car, with |