claims, which made it quite narrow, as its course through the Patent Office clearly demonstrated. It is argued, on behalf of the United States, that Lenke's invention was unpatentable because it embodied nothing more than a natural and normal modification of existing ideas. Such modifications and their advantage were all very clear after the fact; but the old beams had been in use for a number of years and a heavy weight of metal had been used when, by Lenke's device, it was cut down twothirds. Lenke's cargo beam almost universally superseded the old one. The United States used it and it was installed in nearly every pier in the country. No one else had foreseen its advantage. Lenke offered it as a solution of the problem at a minimum cost with a maximum efficiency. The United States conceded in the Court of Claims that Lenke's patent was novel in the sense that there was nothing in the prior art exactly like it, and that it was useful. While thus, in a way, he improved an existing idea, he developed a new idea. The question of its patentability was worked out in the Court of Claims and all the judges concurred in upholding its validity and did not change their conclusion in the second judgment. We see no reason for differing from that conclusion. The Court of Claims based its second judgment against the plaintiff on the strength of section 3477 of the United States Revised Statutes, as construed by this Court in Brothers v. United States, 250 U. S. 88, 89. The section reads as follows: "All transfers and assignments made of any claim upon the United States, or of any part or share thereof, or interest therein, whether absolute or conditional, and whatever may be the consideration therefor, and all powers of attorney, orders, or other authorities for receiving payment of any such claim, or of any part or share thereof, shall be absolutely null and void, unless they are freely made and executed in the presence of at least two attest Opinion of the Court. 275 U.S. ing witnesses, after the allowance of such a claim, the ascertainment of the amount due, and the issuing of a warrant for the payment thereof. Such transfers, assignments, and powers of attorney, must recite the warrant for payment, and must be acknowledged by the person making them, before an officer having authority to take acknowledgments of deeds, and shall be certified by the officer; and it must appear by the certificate that the officer, at the time of the acknowledgment, read and fully explained the transfer, assignment, or warrant of attorney to the person acknowledging the same." In the Brothers case, Mr. Justice Pitney said the claim of Brothers for compensation for a patent he had secured by assignment could not apply to an "unliquidated claim against the Government arising prior to the time he became the owner of the patent. Rev. Stats., § 3477." Counsel for the petitioner here insist that this statement was not necessary to the decision because the conclusion in that case was clearly made to depend on the noninfringement of the patent and that the reference to section 3477 could only be regarded as obiter dictum. It does not make a reason given for a conclusion in a case obiter dictum that it is only one of two reasons for the same conclusion. It is true that in this case the other reason was more dwelt upon and perhaps it was more fully argued and considered than section 3477, but we can not hold that the use of the section in the opinion is not to be regarded as authority except by directly reversing the decision in that case on that point, which we do not wish to do. An elaborate argument has been made to show that the section should not apply to the assignment of claims for infringements of a patent, for the reason that a claim for infringements is not a common law chose in action but grows out of rights created by the statutes covering patents, the provisions for their assignment and for suits by the assignee to be found in sections 4898, 4919, 4921 and other related sections. Crown Die & Tool Co. v. Nye Tool & Machine Works, 261 U. S. 24, 42, 43. But there is no conflict between the patent sections and section 3477. The latter section was passed to protect the Government and prevent frauds upon the Treasury. Western Pacific R. R. Co. v. United States, 268 U. S. 271, 275; Seaboard Air Line Ry. v. United States, 256 U. S. 655, 657; Goodman v. Niblack, 102 U. S. 556, 559, 560. And it would seem that the danger of exploiting and harrassing the Government with the use of assignments of claims for patent infringement was within the general purpose of that section. We come then to the question whether section 3477 and the Brothers case apply to the case before us, and that requires an interpretation of the amending Act of 1918 and its operation upon the rights of the assignee and owner of the patent and its claims for infringement. Exceptions to the general language of section 3477 have been recognized by this Court because not within the evil at which the statute aimed. Seaboard Air Line Ry. v. United States, supra; Western Pacific R. R. Co. v. United States, supra; Goodman v. Niblack, supra; Price v. Forrest, 173 U. S. 410, 421-423; Parrington v. Davis, 285 Fed. 741, 742. We think that the situation created by the provisions of the amending Act of 1918 is such that section 3477 does not apply to all of the assigned claims of the petitioner for infringement under that Act. The Act of June 25, 1910, c. 423, 36 Stat. 851, provided that whenever an invention described in and covered by a patent of the United States should thereafter be used by the United States without license of the owner thereof or lawful right to use the same, such owner might recover reasonable compensation for such use by suit in the Court of Claims. The Act contained a number of provisos, only one of which is important here, namely, that in any such suit the Opinion of the Court. 275 U.S. United States might avail itself of any and all defenses, general or special, which might be pleaded by a defendant in an action for an infringement, as set forth in Title 60 of the Revised Statutes or otherwise. This Court held, March 4, 1918, in Cramp & Sons v. International Curtis Marine Turbine Company, 246 U. S. 28, 42, 45, that the Act of 1910 did not effect a license to the United States or the contractor, making the patented device, to make or use the invention, and that the contractor could be sued for an injunction and for infringement in spite of the operation of that Act. On April 20, 1918, the Acting Secretary of the Navy wrote a letter to the Chairman of the Committee on Naval Affairs of the Senate, in which he said, referring to the Cramp case, that the Department was "confronted with a difficult situation as the result of a recent decision by the Supreme Court affecting the government's rights as to the manufacture and use of patented inventions, and it seems necessary that amendment be made of the Act of June 25, 1910. . . . the decision is, in effect, so far as it is of importance here, that a contractor for the manufacture of a patented article for the government is not exempt, unless he is only a contributory infringer, from injunction and other interference through litigation by the patentee. "A prior decision of the Supreme Court, that in the case of Crozier v. Krupp, had been interpreted as having the opposite meaning, and the department was able up to the time of the later decision, on March 4th last, to proceed satisfactorily with the procuring of such patented articles as it needed, leaving the matter of compensation to patentees for adjustment by direct agreement, or, if necessary, by resort to the Court of Claims under the above mentioned act of 1910. Now, however, manufacturers are exposed to expensive litigation, involving the possibilities of prohibitive injunction, payment of royalties, rendering of accounts, and payment of punitive damages, and they 331 Opinion of the Court. are reluctant to take contracts that may bring such severe consequences. The situation promises serious disadvantage to the public interests, and in order that vital activities of this department may not be restricted unduly at this time, and also with a view of enabling dissatisfied patentees to obtain just and adequate compensation in all cases conformably to the declared purpose of said act, 1 have the honor to request that the act be amended by the insertion of a proper provision therefor in the pending naval appropriation bill." In response to this communication, the Act of July 1, 1918, amending the Act of 1910, was adopted. (See Wood v. Atlantic Gulf & Pacific Co., 296 Fed. 718, 720, 721, and Congressional Record, 65th Congress, Second Session, Proceedings of June 18, 1918, p. 7961). The amendment (c. 114, 40 Stat. 704, 705) reads as follows: "That whenever an invention described in and covered by a patent of the United States shall hereafter be used or manufactured by or for the United States without license of the owner thereof or lawful right to use or manufacture the same, such owner's remedy shall be by suit against the United States in the Court of Claims for the recovery of his reasonable and entire compensation for such use and manufacture." This is followed by the same provisos as in the Act of 1910, which need not be repeated here. The purpose of the amendment was to relieve the contractor entirely from liability of every kind for the infringement of patents in manufacturing anything for the Government and to limit the owner of the patent and his assigns and all claiming through or under him to suit against the United States in the Court of Claims for the recovery of his reasonable and entire compensation for such use and manufacture. The word "entire" emphasizes the exclusive and comprehensive character of the remedy provided. As the Solicitor General says in his |