Opinion of the court. Mr. Justice NELSON. This is an appeal from the Circuit Court of the United States for the District of Columbia. The bill was filed by the plaintiffs against the defendant, Bacon, to compel him to surrender and cancel letters patent for a new and useful machine for folding paper, granted 10th of August, 1858. Both parties set up a claim to the invention as assignees of John North, the inventor. The assignments to the plaintiffs were made under the dates of 12th of August, 1858, and 7th July, 1859. The defendant claims under an agreement made between North and the American Book and Paper-Folding Company, dated 6th of February, 1854, and between the same company and Newell and John North, 2d of May, 1854, and by a subsequent verbal agreement between the defendant and John North, some time in May, 1856. According to the terms of the two written agreements between North and the American Company, the former stipulated to engage in the service of the company, and devote himself to the making of improvements in paper-folding machines for a compensation mentioned; and, further, that all improvements and inventions made or discovered should be the property of the company, and that he would take all proper steps for the purpose of procuring patents for said improvements. It was further stipulated that this agreement may be terminated by North on giving three months' notice after having served one year, and the company at any time on giving thirty days' notice. This company, having subsequently resolved to close their business, gave a written notice to North on the 30th of May, 1857, that his services would be no longer required, and, about the same time, sold at auction, among other things, their interest in the improvements made by North in paper-folding machines, including a patent issued 15th of April, 1856, to North, and another issued to E. N. Smith, 27th of November, 1849, and reissued 7th of January, 1851, which interests and property were purchased by one Anson Hardy; and on the 1st of July, 1856, said Hardy assigned all his interest in the property to Bacon, the defendant. The defendant, after his purchase of these machines, made a verbal arrangement with North to enter into his service and devote himself to making improvements in folding machines, upon the same terms and conditions as those under which he had been previously engaged with the company. This arrangement continued till about the middle of July, 1857, when he left the service of the defendant and engaged in the manufacture of sewing machines. Now, it is claimed by the defendant that the inventions or improvements embraced in the paper-folding machine in ques Opinion of the court. tion were the fruits of the labors of North while engaged in his, the defendant's, service, and when he was entitled to the benefit of his discoveries, or when he (North) was engaged in the service of the American Paper-Folding Company, who were entitled to the benefit of these discoveries, and which passed to him, the defendant, by assignment. The right, as thus derived, constitutes the title of the defendant to the invention and patent in controversy. It has already been stated that among the property which passed to the defendant from the American Company through Hardy was the patent to North for a paper-folding machine issued 15th of April, 1856. The labors of North while in the service of defendant were devoted to improvements upon this machine, and it is this machine, as improved in July, 1857, when North left the service of the defendant, that it is claimed embodied the invention and improvements in question, and for which a patent was issued to the defendant 10th of August, 1858. The circumstances under which this patent was issued will be stated hereafter. For the present, our inquiry is whether or not North made these discoveries while engaged in the service of the defendant or in the service of the American Folding Company. North, who was made a defendant and a party on the record, was called as a witness on the part of the plaintiffs, and very fully examined on both sides. No objection is taken to the competency of his testimony before the officer taking it, nor in the brief in this court, and we must regard it, therefore, as admitted by consent. This witness, after giving a history of the machine, of its exhibition at the fair of the American Institute in the fall of 1856, and also at Appletons' bindery, in Franklin street, in the city of New York, in February, 1857, and of some improvements made upon it at that place, states that about the first of June, 1857, he removed the machine to a shop in Middletown, Connecticut, and worked upon it there some six weeks, endeavoring to improve it, but with no good results; gave up the effort and went into other businessmaking sewing machines. This was about the middle of July, 1857. The difficulties in the working of the machine while at Appletons' and at Middletown were in the adjustment to correspond with the different signatures-the register, also, was imperfectand a fullness in the sheet which wrinkled it. This machine was afterwards removed to Colt's armory in Hartford, Connecticut; and we have the testimony of E. K. Root-a witness for the defendant, and mechanical engineer-who examined it there, and saw it in operation. He was asked-"Of the sheets Opinion of the court. you have seen folded on that machine what proportion were crimped or wrinkled, and to what amount?" Answer: "My impression is that about one half were wrinkled more or less--pretty much all on one side of the machine-so much as to be objectionable." "To what extent, if at all, would you consider the amount of wrinkling you observed as affecting of itself the practical value of the machine?" Auswer: "I should say it would prevent its use on all good book work." This testimony is confirmed by two other witnesses, Gavet and Mathews. The machine to which these witnesses refer and speak of embodied all the improvements ever made upon it by North. Indeed, it is admitted he made none after the middle of July, 1857, and it is quite clear from the evidence that it was an unsuccessful experiment as a practical folding machine, and abandoned by him as such. In the spring of 1858, North, at the solicitation of Mathews, who had charge of the bindery department of the Appletons, turned his attention to the invention of a machine that would fold the size of duodecimo sheets, all the previous machines that had been constructed having been adapted only to the folding of octavo volumes. As five sixths of the business of book folding was of the small size, the invention was regarded as a great desideratum. This is the machine afterwards produced by North, and for which he applied to the Patent Office for a patent. The necessary papers, model, and certificate of payment of the patent fee were forwarded to the office 27th of May, 1858. The machine will fold books of both octavo and twelve-mo size with entire success. The papers and model were filed in the Patent Office 10th June, 1858, and the patent issued to S. T. Bacon, the defendant, instead of to John North, the inventor, on the 10th of August following, and this without any previous notice to him. How this happened in the Commissioner's office has not been explained. It was a very grave irregularity. The specification on file was in the name of North, the application in his name, and the patent fee paid by him. We have seen the defendant, to whom it was issued, had no right to it, legal or equitable. The officer must have been imposed upon by the use of the old machine of 1856, which we have seen was but an unsuccessful experiment, and abandoned. The plaintiffs, as assignees of North, have made out a clear right to the patent, and the decree of the court below must be reversed and the cause remitted, with instructions to enter a decree for the plaintiffs, directing the defendant to surrender the patent to be canceled. Statement of the case. EAMES v. GODFREY. Where a patent is for a combination of distinct and designated parts, it is not infringed by a combination which varies from that patented, in the omission of one of the operative parts and the substitution therefor of another part substantially different in its construction and operation, but serving the same purpose. GODFREY sued Eames in the Circuit Court of the United States for the District of Massachusetts, in an action on the case for infringing a patent for a new and useful improvement it boot-trees, of which patent he, Godfrey, was the assignee. The defendant pleaded not guilty, and gave notice of special matters of defense. The case was tried by a jury, who found the defendant guilty, and assessed the damages at $2,177 50. The patent was for a combination of mechanical powers for a new and useful improvement in boot-trees, and included a certain mechanism for distending the leg of the boot-tree. The plaintiff did not claim that the defendant had used the same mechanism that he did for distending the leg of the boot-tree, but that the defendant had used all the other parts of his combination, and that the mechanism which the defendant used, although differing in construction and operation from that described in the patent, yet performed the same function. The defendant contended, that not having used the mechanism described in the patent for distending the leg of the boot-tree, although he had used the other parts of the combination, he was not guilty of infringing the patent, and requested the court so to rule. The court refused to rule as requested, but instructed the jury "that to make out an infringement of the claim for combination, it was not necessary for the plaintiff to show that the mechanism for distending used by the defendant and its mode of operation were the same with that described in the plaintiff's patent for the purpose of distending the boot-tree; and that if said mechanism for distending the leg, &c., used by the defendant was not the same mechanism, operating in the same manner as that described in the plaintiff's patent for the same purpose; still, if there were in the defendant's machine a mechanism performing the same function as that performed by plaintiff's distending mechanism, and if this was combined with the other parts in the manner in which the distending mechanism described in the plaintiff's patent was combined, it was an infringement of said patent, and the defendant would be liable therefor." The defendant excepted to the instructions given, and the refusal of the court to instruct as prayed for. Opinion of the court. On error here the instructions and refusal, as aforesaid, were the points before this court. Mr. F. A. Brooks, for the plaintiff in error; Mr. Causten Browne, contra. Mr. Justice DAVIS delivered the opinion of the court. The patent in controversy was for a combination of mechanical powers to effect a useful result, and such a patent differs essentially in its principles from one where the subject-matter is new. The law is well settled by repeated adjudications in this court and the Circuit Courts of the United States that there is no infringement of a patent which claims mechanical powers in combination, unless all the parts have been substantially used. use of a part less than the whole is no infringement. The In Prouty & Mears v. Ruggles, 16 Peters, 341, the law is well. considered. The patent there was for the combination of certain parts of a plough, arranged together so as to produce a certain effect. The suit was for an infringement. The court below had charged the jury that unless the whole combination was substantially used in the defendant's plough it was no violation of the plaintiff's patent. Chief Justice Taney, in deciding the case, said: "None of the parts referred to are new, and none are claimed as new; nor is any portion of the combination less than the whole claimed as new, or stated to produce any given result. The end in view is proposed to be accomplished by the union of all, arranged and combined together in the manner described. The use of any two of these parts only, or of two combined with a third, which is substantially different in form or in the manner of its arrangement and connection with the others, is, therefore, not the thing pat ented. It is not the same combination if it substantially differs from it in any of its parts,' Testing this case by these principles, the court erred in charging the jury as it did, and in refusing to instruct as asked by the defendant. There is nothing in the record that shows in what manner the mechanism used by Eames, in distending the leg of the boot-tree, differed from that claimed in the patent. It is stated that the mechanism used by Eames was different in its construction and operation, but how far the difference extended, we are left to conjecture. It is fair to presume, in the absence of proof, that it was essentially different. If, however, the mechanism used by Eames was not substantially different in its form or the manner of its arrangement from the mechanism used by Godfrey, there was |