MR. JUSTICE MURPHY delivered the opinion of the Court.

The question is whether respondent, Dickerson, may recover a judgment against the United States upon a cause of action founded upon § 9 of the Act of June 10, 1922, c. 212, 42 Stat. 625, 629-630.

Section 9 provides that after the 1st of July, 1922, an enlistment allowance shall be paid "to every honorably discharged enlisted man . . . who re-enlists within a period of three months from the date of his discharge." Respondent, who was honorably discharged upon the termination of an enlisted period ending on the 21st of July, 1938, re-enlisted on the following day, the 22nd, for a period of three years, but was not paid an enlistment allowance. He thereupon brought this action in the Court of Claims. It is conceded that § 9, if not repealed or suspended at the date of his re-enlistment, would entitle him to the sum of seventy-five dollars.

The Government opposed the action before the Court of Claims on the ground that § 402 of Public Resolution No. 122, June 21, 1938, c. 554, 52 Stat. 809, 818-819, suspended the allowance for re-enlistment during the fiscal year ending June 30, 1939. Section 402 contains a proviso, appended to an appropriation for the Rural Electrification Administration, that "no part of any appropriation contained in this or any other Act for the fiscal year ending June 30, 1939, shall be available for the payment" of any enlistment allowance for "re-enlistments made during the fiscal year ending June 30, 1939, notwithstanding the applicable portions of sections 9 and 10" of the Act of June 10, 1922.

The Court of Claims entered judgment for respondent on the ground that § 402, while it restricted the funds available for payment of the allowance, did not suspend or repeal § 9. 89 Ct. Cls. 520. Because of the importance of the issue in the administration of the revenues, we granted certiorari. 309 U.S. 647.

There can be no doubt that Congress could suspend or repeal the authorization contained in § 9; and it could accomplish its purpose by an amendment to an appropriation bill, or otherwise. United States v. Mitchell, 109 U.S. 146, 150; Mathews v. United States, 123 U.S. 182; Dunwoody v. United States, 143 U.S. 578; Belknap v. United States, 150 U.S. 588, 593; United States v. Vulte, 233 U.S. 509, 515. See United States v. Langston, 118 U.S. 389. The question remains whether it did so during the fiscal year ending on the 30th of June, 1939.

Section 9 remained in full force and effect during the eleven fiscal years ending on the 30th of June, 1923 to 1933, after which date it was suspended during the ensuing four fiscal years by a provision inserted in various appropriation acts. Section 18 of the Economy Act of March 3, 1933, c. 212, 47 Stat. 1489, 1519, provided that "So much of sections 9 and 10 of the Act . . . approved June 10, 1922 . . . as provides for the payment of enlistment allowances to enlisted men for re-enlistment within a period of three months from date of discharge is hereby suspended as to re-enlistments made during the fiscal year ending June 30, 1934." This provision, which concededly suspended the authorization for the enlistment allowance, was continued in full force and effect for the fiscal years ending on the 30th of June, 1935, 1936 and 1937, by its insertion in the Economy Provisions of the Independent Offices Appropriation Act for the fiscal year 1935 and in the Treasury-Post Office Appropriation Acts for the fiscal years 1936 and 1937.

The Second Deficiency Appropriation Bill of May 28, 1937, c. 277, 50 Stat. 213, 232, also contained a provision affecting the enlistment allowance, but the form of words used was changed. That Act as passed by Congress provided that "no part of any appropriation contained in this or any other Act for the fiscal year ending June 30, 1938, shall be available for the payment of enlistment allowance to enlisted men for re-enlistment within a period of three months from date of discharge as to re-enlistments made during the fiscal year ending June 30, 1938, notwithstanding the applicable provisions of sections 9 and 10 of the Act" approved June 10, 1922. The identical provision, with the exception of the dates, was appended as a proviso to § 402 of Public Resolution 122, copied above, and was made applicable during the fiscal year ending on the 30th of June, 1939.

The provision inserted in the Second Deficiency Appropriation Bill for 1937 was introduced on the floor of the Senate as an amendment by Senator Byrnes. In response to questions concerning the amendment, the Senator stated (81 Cong. Rec. 4426):

". . . the language of the amendment has been carried ordinarily in the Treasury and Post Office Appropriation Bill, but was not carried in that appropriation bill this year, and is therefore proposed to be included in the bill now before us.

. . . . .

The effect of it is simply to carry the same limitation that has been carried for years in the appropriation bills.

. . . . .

Its purpose is to continue the appropriation situation that has existed for years, so that no bounty shall be paid for re-enlistment in the military and other uniformed services."

The amendment was thereupon adopted in the Senate without recorded opposition, and was sent to conference. The House managers, in reporting the amendment to the House, described it as "Continuing during the fiscal year 1938 the suspension of the re-enlistment gratuity for enlisted personnel of the Army, Navy, Marine Corps, and Coast Guard." 81 Cong. Rec. 5084. The course of the debate amply discloses that the House regarded the amendment as continuing during the fiscal year 1938 the same restriction on the enlistment allowance as the provision inserted in earlier appropriation bills. It was then adopted by the House. 81 Cong. Rec. 5091.

The identical provision (except as to the dates), eventually appended to § 402 of Public Resolution 122, was introduced as an amendment to the Second Deficiency Appropriation Bill for the fiscal year 1938 (H.R. 10851, 75th Cong., 3d Sess.), then pending in the House. 83 Cong. Rec. 8522-8569. A point of order was made against the amendment on the ground that it was legislation in an appropriation bill; Representative Woodrum, who had charge of the amendment, admitted that the point of order was good, and the Chair sustained it. 83 Cong. Rec. 8567. The amendment was then offered in the Senate, where the Presiding Officer also sustained a point of order that it was legislation in an appropriation bill. 83 Cong. Rec. 9189.

The provision was thereafter included by the conference committee as a proviso to § 402 of H.J. Res. 679 (which later became Pub. Res. No. 122). See 83 Cong. Rec. 9512, 9677. It was passed by the Senate without much debate. In the House, the debate disclosed that the amendment had the same purpose and effect as the provision inserted in the various appropriation bills for the preceding years. Representative Woodrum, in presenting the amendment to the House, described it as follows (83 Cong. Rec. 9677):

". . . we are providing a further inhibition for 1 year against payment of the re-enlistment allowances in the military and naval services.

"No re-enlistment allowances have been paid for the past 5 fiscal years in any of the services, and in the absence of permanent law stopping it, the inhibition has been shuttled about in economy bills and appropriation bills at one time or another. We have not paid them for 5 years, and the latter part of this amendment now before the House is a Senate amendment which discontinues for another year the payment of the re-enlistment allowances."

The opponents of the amendment, while questioning its wisdom, were in general agreement with its sponsors concerning its purpose and effect. 83 Cong. Rec. 9678-9679. The amendment was then adopted by the House. 83 Cong. Rec. 9679.

We are of opinion that Congress intended in § 402 to suspend the enlistment allowance authorized by § 9 during the fiscal year ending on the 30th of June, 1939. The legislative history, summarized above, discloses that Congress intended the legislation concerning the allowance during the fiscal years 1938 and 1939 as a continuation of the suspension enacted in each of the four preceding years. The adoption in the act of May 28, 1937, of different terminology might in other circumstances indicate an intent to change the object of the legislation. Compare Brewster v. Gage, 280 U.S. 327, 337; Crawford v. Burke, 195 U.S. 176, 190; Pirie v. Chicago Title Trust Co., 182 U.S. 438, 448. But the drawing of such an inference is a workable rule of construction, not an infallible guide to legislative intent, and cannot overcome more persuasive evidence where, as here, it exists. Compare Boston Sand Gravel Co. v. United States, 278 U.S. 41, 48.

The respondent contends that the words of § 402 are plain and unambiguous and that other aids to construction may not be utilized. It is sufficient answer to deny that such words when used in an appropriation bill are words of art or have a settled meaning. See United States v. Perry, 50 F. 743, 748 (C. C.A. 8th). The very legislative materials which respondent would exclude refute his assumption. It would be anomalous to close our minds to persuasive evidence of intention on the ground that reasonable men could not differ as to the meaning of the words. Legislative materials may be without probative value, or contradictory, or ambiguous, it is true, and in such cases will not be permitted to control the customary meaning of words or overcome rules of syntax or construction found by experience to be workable; they can scarcely be deemed to be incompetent or irrelevant. See Boston Sand Gravel Co. v. United States, supra, at 48. The meaning to be ascribed to an Act of Congress can only be derived from a considered weighing of every relevant aid to construction. These lead to the conclusion that the judgment of the court below must be

Reversed.

The CHIEF JUSTICE, MR. JUSTICE McREYNOLDS, MR. JUSTICE STONE and MR. JUSTICE ROBERTS are of opinion that the judgment should be affirmed on the views expressed by the Court of Claims.