delivered the opinion of the Court:

We find little difficulty in determining the matter in dispute. The act of April 28th, 1904, repealed the tax upon building associations prescribed in the act of July 1st, 1902. It substituted a new provision for their taxation. The slight verbal changes in the new provision are immaterial. By this act Congress directed, speaking from its date, April 28th, 1904, that building associations should pay the collector of taxes of this District “2 per centum per annum on their entire gross earnings for the preceding year ending June 80th.” This means that the plaintiff became subject to a tax of 2 per cent on $108,252.91, its entire gross earnings for the preceding year ending June 30th, 1903. There can be no doubt that in respect of building associations the act we are considering speaks from its date, April 28th, 1904. The tax was payable by the plaintiff in May of that year. The 4 per cent rate had been repealed. The 2 per cent rate had been enacted. The plaintiff tendered the lawful tax in May, 1904, and the defendant should have accepted such lawful tax. There is no room for discussing whether the act of April 28th, 1904, was in its operation retroactive or prospective in respect of the tax on building associations. It went into effect on the day of its approval so far as building associations are concerned. In amending sec. 6 it reduced the tax upon savings banks, and carefully provided that the amendment should have effect hereafter, beginning with the fiscal year July 1st, 1904, and made other amendments to take effect hereafter, and certain amendments are prospective. Congress intended to relieve building associations from a tax it deemed too onerous upon them, and it plainly expressed its purpose to relieve them by an absolute repeal of the 4 per cent rate before the time that rate was payable, and substituted a 2 per cent rate, and in terms applied that rate to the entire gross earnings of building associations for the preceding year ending June 30th, 1903.

*580The defendant’s argument that the act which went into effect April 28th, 1904, should be construed to tax gross earnings for the preceding year ending June 30th, 1904, asks us to legislate and to alter and amend a plain and clear enactment which admits of no doubt. It nowhere appears in this record that the gross earnings returned in this case were not the entire gross earnings. It is not significant that the assessment on the tax books, made under the law as it was, remained at 4 per cent. The acts of assessors do not limit or vary the power of Congress. Indeed, in both acts when the return of gross earnings was duly made and its verity not questioned, there was no difficulty in respect of assessment. As the Supreme Court said in another tax case: “No other assessment than that made by the statute was necessary to determine the extent of the bank’s liability. An assessment is only determining the value of the thing taxed, and the amount of the tax required of each individual. It may be made by designated officers or by the law itself. In the present case the statute required every savings bank to pay a tax of 5 per cent on all undistributed earnings made, or added during the year to their contingent funds. There was no occasion or room for any other assessment. This was a charge of a certain sum upon the bank, and without more it made the bank a debtor.” Dollar Sav. Bank v. United States, 19 Wall. 227, 240, 22 L. ed. 80, 82.

The learned court below committed no error in deciding that the act of April 28th, 1904, was not intended to operate prospectively as the defendant contended by its demurrer.

The court below did not err in deciding that the payment of the money claimed in this action was an involuntary payment, and that the appellee was therefore entitled to recover. We have stated the circumstances under which this payment was made. “A payment made to relieve the person from arrest or the goods from seizure is a payment on compulsion; and so is the payment to prevent a seizure when it is threatened. So with still greater reason is the payment which the officer secures by making sale of goods seized. But it is not necessary for the taxpayer to wait for his goods to be sold, or even to be seized. *581If the officer calls upon the person taxed, and ‘demands a sum of money under a warrant directing him to enforce it, the party of whom he demands it inay fairly assume that, if he seeks to act under the warrant at all, he will make it effectual. The demand itself is equivalent to a service of the writ on the person.’ ” 2 Cooley, Taxn. 3d ed. 1505. And Judge Dillon says: “The payment by the plaintiff must have been made upon compulsion, as, for example, to prevent the immediate seizure of his goods or the arrest of the person, and not voluntary.” 2 Dill. Mun. Corp. 4th ed. sec. 940. “Money paid by a person to prevent an illegal seizure of his person or property by an officer claiming authority to seize the same * * * may be recovered back in an action for money had and received, on the ground that the payment was compulsory or by duress or extortion.” Id. sec. 942. These authorities were approved by this court, and it was held in District of Columbia v. Chapman, 25 App. D. C. 98, that a payment of money made under circumstances like those under which the payment in this case was made entitled the plaintiff in such case to maintain an action like this for its recovery. The learned court below committed no error in this respect.

The judgment below must be affirmed, with costs, and it is so ordered. Affirmed.