Opinion of the court. took to divest a vested right contrary to the law of the land and without due process of law. As a basis for his argument he assumes that under the statute of the State relating to the opening and improvement of streets in the city of New York, passed in 1813, and which is one of the laws referred to in the act of 1869, and made applicable to the improvement authorized, the proceedings of the commissioners, when their report was confirmed by the Supreme Court, were so far final and conclusive of the right of the city to the property and of the plaintiff to the award, that neither were subject to any legis lative or judicial interference. The same position here urged was relied upon in the Supreme Court and the Court of Appeals of the State on the appeal from the order vacating the confirmation taken by one of the parties to whom an award had been rendered.* And in both courts it was held that the provision in the statute of 1813, which declares that the report of the commissioners of estimate and assessment, when confirmed by the court, shall be "final and conclusive," only meant that no appeal should lie from the order of confirmation to a higher court, and that it did not preclude an application to the court to vacate the order for mistake, irregularity, or fraud in the proceedings; that the Supreme Court had power to hear such motions in ordinary cases of judgments and orders in suits there pending, and that no reason existed against the possession or exercise of the power in cases of this character. The provision in question, said the Court of Appeals, "plainly never intended to give a vested interest in a mistake and irregularity or fraud, whereby important rights of property were acquired or lost. It had reference simply to an appeal upon the merits, and is satisfied with that. All judgments are liable to be set aside for fraud, mistake, or irregularity, and a vested interest therein is subject to that liability." * In the Matter of Widening Broadway, 61 Barbour, 483; and 49 New York, 150. Opinion of the court. The Supreme Court held that the act of 1871 was constitutional. The Court of Appeals held that, independent of the act and without passing upon its validity, the Supreme Court had authority to set aside the order upon the grounds stated. If the views of either of these courts be correct, they dispose of the questions in this case. And the construction of the statute of the State by the Court of Appeals, and its decision as to the powers of the Supreme Court of the State to correct or set aside its own judgments, upon application within reasonable time, for mistake, irregularity, or fraud, are conclusive upon us. There is, therefore, no case presented in which it can be justly contended that a contract has been impaired. It may be doubted whether a judgment not founded upon an agreement, express or implied, is a contract within the meaning of the constitutional prohibition. It is sometimes called by text-writers a contract of record, because it establishes a legal obligation to pay the amount recovered, and, by fiction of law, where there is a legal obligation to pay a promise to pay is implied. It is upon this principle, says Chitty, that an action in form ex contractu will lie on a judgment of a court of record.* But it is not perceived how this fiction can convert the result of a proceeding, not founded upon an agreement express or implied, but upon a transaction wanting the assent of the parties, into a contract within the meaning of the clause of the Federal Constitution which forbids any legislation impairing its obligation. The purpose of the constitutional prohibition was the maintenance of good faith in the stipulations of parties against any State interference. If no assent be given to a transaction no faith is pledged in respect to it, and there would seem in such case to be no room for the operation of the prohibition. In the proceeding to condemn the property of the plaintiff for a public street, there was nothing in the nature of a contract between him and the city. The State, in virtue of her *Chitty on Contracts, Perkins's edition, 87. Opinion of the court. right of eminent domain, had authorized the city to take his property for a public purpose, upon making to him just compensation. All that the constitution or justice required was that a just compensation should be made to him, and his property would then be taken whether or not he assented to the measure. The proceeding to ascertain the benefits or losses which will accrue to the owner of property when taken for public use, and thus the compensation to be made to him, is in the nature of an inquest on the part of the State, and is necessarily under her control. It is her duty to see that the estimates made are just, not merely to the individual whose property is taken, but to the public which is to pay for it. And she can to that end vacate or authorize the vacation of any inquest taken by her directiou, to ascertain particular facts for her guidance, where the proceeding has been irregularly or fraudulently conducted, or in which error has intervened, and order a new inquest, provided such methods of procedure be observed as will secure a fair hearing from the parties interested in the property. Nor do we perceive how this power of the State can be affected by the fact that she makes the finding of the commissioners upon the inquest subject to the approval of one of her courts. That is but one of the modes which she may adopt to prevent error and imposition in the proceedings. There is certainly nothing in the fact that an appeal is not allowed from the action of the court in such cases, which precludes a resort to other methods for the correction of the finding where irregularity, mistake, or fraud has intervened. Until the property is actually taken, and the compensation is made or provided, the power of the State over the matter is not ended. Any declaration in the statute that the title will vest at a particular time, must be construed in subordination to the constitution, which requires, except in cases of emergency admitting of no delay, the payment of the compensation, or provision for its payment, to precede the taking, or, at least, to be concurrent with it. The statute of 1818 would also seem so far to modify the act of 1813 as Syllabus. to require a formal acceptance of the land on the part of the corporation before the title can vest.* The objection to the act of 1871, that it impairs the vested rights of the plaintiff, and is, therefore, repugnant to the constitution of the State, is already disposed of by what we have said upon the first objection. There is no such vested right in a judgment, in the party in whose favor it is rendered, as to preclude its re-examination and vacation in the ordinary modes provided by law, even though an appeal from it may not be allowed; and the award of the commissioners, even when approved by the court, possesses no greater sanctity. JUDGMENT AFFIRMED. LITTLEFIELD V. PERRY. 1. Where one instrument, duly recorded in the Patent Office, contains in unmistakable language, an absolute conveyance by a patentee of his patent and inventions described (in this case applications of a principle of heating furnaces for houses, heating stoves, steam boilers, &c.), and all improvements thereon, within and throughout certain States, and an agreement by the assignee to pay a royalty on all patented articles sold, with a clause of forfeiture in case of non-payment, or neglect, after due notice, to make and sell the patented articles to the extent of a reasonable demand therefor, the grantee will not, by an agreement supplementary to such assignment and of even date but not recorded, be reduced into a mere licensee as respects a right to sue in the Federal courts, for infringement within the assigned territory, by the fact that in the supplementary agreement the parties declare that nothing in the grant shall give the assignee the right to apply the principle of the invention to one special purpose (in this case to the heating of several rooms in a house by furnaces erected in the cellar), "the same being intended to be reserved" by the patentce. And this is so, although the supplementary and unrecorded agreement be referred to in the recorded one. The reservation will be regarded as the grant back of a mere license from the assignee to the patentee. 2. Such grantee, or one claiming under hím, may accordingly, as assignee, under the Patent Acts, sue in the Federal courts to prevent an infringement upon his right. * Strang v. New York Rubber Co., 1 Sweeny, 86, 87. Syllabus. 8. Even though this were not so, and he not technically an assignee, such a grantee may, under the Patent Act. which provides "that all actions, suits, controversies, and cases arising under any law of the United States granting or confirming to inventors the exclusive right to their inventions or discov eries shall be originally cognizable, as well in equity as at law, in the Circuit Courts, &c.," maintain a suit in his own name in the Federal court against the patentee, alleged to infringe. He has the exclusive right to the use of the patent for certain purposes within a defined territory, and so holds a right under the patent. Alleging infringement, a construction of the patent is involved; this raises a question "under" the "law." That such a suit may involve the construction of a contract as well as of the patent, will not oust the court of its jurisdiction. If the patent is involved it curries with it the whole case. 4. Semble. Where the patentee himself is infringing the rights of his own licensee, and the licensee (not being able to sue the patentee in the usual way in which a licensee sues an infringer, i. e, in the patentee's name) is remediless so far as the Federal courts are concerned, unless he can sue in his own name--he may so sue in equity, which regards substance and not form. The cases of strangers and the patentee himself distinguished in the category of infringement. 5. Where assignees of a patent grant to A, and afterwards, not regarding that grant, grant, though without warranty, to B., if A. reconvey to them, B. has the right by estoppel against his grantors. 6. Where a person had a patent for "a coal-burner so constructed as to produce combustion of the inflammable gases of anthracite coals," and had also a pending application for another improvement in stoves, devised for the purpose of economizing and burning the gases generated by the combustion of anthracite coals ;" and afterwards executed a grant, which (after reciting that he held a patent "for a coal-burner so constructed as to produce combustion of the inflammable gases of anthracite coals," and that he had "made application for letters-patent securing to him a certain improvement in the invention so as aforesaid patented to him"), then proceeded to assign all the right, title, and interest which he then had, or might thereafter have, "in or to the aforesaid inventions, improvement, and patent, or the patent or patents that may be granted for said inventions or any improvement therein”—he will not be allowed-on his beforementioned "application" being rejected, and on his getting subsequently to the date of the grant and of the rejection, a patent for an improvement in stoves, so devised as to burn the gaseous and more inflammable elements of the coal in contact with its more refractory portions, and thus secure a more complete combustion of them both," which his grantee asserts to be for the same thing essen tially as was the rejected application, and so to have passed under the grant-to deny that the application was for an "improvement" on the first patent. He is estopped by his grant describing it as an improvement on the first patent, to do so. Accordingly, if the second patent be, in view of the court, for essentially the same thing as was the re |