Opinion of the Court. and horses, or that such sale would work that kind of mischief which justifies the interference of equity in the application of a preventive remedy. Nor did the mere fact that its property might be used in the conduct of interstate commerce give jurisdiction. But in addition to all this, since 1873 there has been a statute in existence in Tennessee, providing a remedy at law, which has been pronounced by this court simple and effective. Tennessee v. Sneed, 96 U. S. 69. Under that act, where an officer charged by law with the collection of revenue due the State takes any steps for the collection of the same, a party conceiving the tax to be unjust or illegal may pay it under protest, and sue the officer to recover the money back, and if the court determines that it was wrongfully collected, then, upon its certificate to that effect, the comptroller "shall issue his warrant for the same, which shall be paid in preference to other claims on the treasury." And the act further provides that there shall be no other remedy in any case of the collection of revenue, and no writ for the prevention of such collection or to hinder and delay it shall in any wise issue, either injunction, supersedeas, prohibition or any other writ or process whatever. This act has been sanctioned and applied by the courts of Tennessee. Nashville v. Smith, 86 Tennessee, 213; Railroad v. State, 8 Heiskell, 663, 804. It is, as counsel observe, similar to the act of Congress forbidding suit for the purpose of restraining the assessment or collection of taxes under the internal revenue laws, in respect to which this court held that the remedy by suit to recover back the tax after payment, provided for by the statute, was exclusive. Snyder v. Marks, 109 U. S. 189; 14 Stat. 152, 475. Legislation of this character has been called for by the embarrassments resulting from the improvident employment of the writ of injunction in arresting the collection of the public revenue; and, even in its absence, the strong arm of the Court of Chancery ought not to be interposed in that direction except where resort to that court is grounded upon the settled principles which govern its jurisdiction. It is asserted by counsel that a court of equity has jurisdic Opinion of the Court. tion to restrain the collection of a tax when the tax is wholly illegal and void, and that such jurisdiction has been uniformly exercised in the Federal courts. Allen v. Balt. & Ohio Railroad, 114 U. S. 311; Osborn v. Bank of the United States, 9 Wheat. 738; Cummings v. National Bank, 101 U. S. 153; and Dodge v. Woolsey, 18 How. 331, are cited; but the jurisdiction will be found to have rested on other grounds than merely the unconstitutionality of the taxes involved. In Allen v. Baltimore & Ohio Railroad, Allen was auditor of public accounts of Virginia, and Hamilton, treasurer of Augusta County, in that State. The auditor had assessed certain railroads upon their real estate, not having any rolling stock, as being in default for non-payment of taxes assessed by the board of public works, and had placed copies of the assessment in the hands of the defendant Hamilton, as treasurer of Augusta County, for collection, in pursuance of which he had levied upon certain cars and locomotives belonging to complainant, and used by it in operating said railroads as lessee, for part of the taxes, and threatened to make further levy upon other cars and engines and sell them for payment of said taxes; and the bill prayed for an injunction on the several grounds of irreparable damage, avoidance of multiplicity of suits, removal of cloud upon title, etc. It was admitted in the case that if the property of the complainant levied on should be sold, great sacrifice and loss must result therefrom, and that the withdrawal of the rolling stock and machinery proposed to be sold would cause serious and prolonged embarrassment to complainant's business; that much delay must accrue before said rolling stock and maoninery, if sold, could be replaced; and that it would be difficult, if not impracticable, to ascertain and estimate with even proximate certainty the losses and damages which would result to complainant from the sale, so that although the estate of Hamilton might be sufficient to meet any verdict for damages if the sale should be adjudged to be illegal, the pecuniary value of complainant's losses and damages could not be properly and adequately ascertained and fixed by the verdict of a jury. This admission made a case of irreparable injury. Opinion of the Court. In Osborn v. Bank of the United States, the court held that the effect of the law of Ohio in question would be the expulsion of the bank from the State; that the injury done thereby would be in its nature irreparable; and further that as by the amended and supplemental bill it appeared that the money and notes of the bank were in the possession of one of the defendants and kept separate and apart from all other money and notes, the principle of preventing the transfer of a specific article, which if transierred might be lost to the owner, applied. In Cummings v. National Bank, the jurisdiction was ma.ntained upon the ground of preventing multiplicity of suits, as well as that the remedy by injunction against an illegal tax was expressly granted by a statute of the State whose levy of taxes was drawn in question. The ground upon which Dodge v. Woolsey proceeded was that a stockholder had a remedy in chancery against the directors of his corporation to restrain them from doing acts. which would amount to a violation of the charter, or to prevent any misapplication of their capital or profits, which might lessen the value of the shares, if the acts intended to be done amounted to a breach of trust or duty, and that the refusal of the directors to resist the collection of a tax, which they themselves believed to have been imposed upon them in violation of their charter, was in legal effect a breach of trust. The Circuit Court held the act of 1873 inapplicable to an unconstitutional tax, upon the authority of Poindexter v. Greenhow, 114 U. S. 270. That was an action of detinue brought by Poindexter, a taxpayer, against Greenhow, treasurer of Richmond, Virginia, for a desk belonging to plaintiff, seized and taken by Greenhow for the purpose of raising the tax claimed to be due from plaintiff after he had tendered coupons in payment thereof in pursuance of the Virginia act of 1871, making the coupons receivable for taxes. In 1882, Virginia passed an act providing that, in case of proceedings instituted against a taxpayer for the collection of his tax, notwithstanding his tender of coupons in payment thereof, he should pay the tax under protest in lawful money, and then Opinion of the Court. sue the officer for the amount, and if it should be determined that it was wrongfully collected, the amount should be returned, and that no writ of injunction, supersedeas, mandamus, prohibition or other writ whatever should be issued to hinder or delay the collection of the tax. At the same time several other acts were passed calculated to impede the operation of the act of 1871. This court held that the tender was equivalent to payment; that the taxpayer had the right to stand upon such payment once made; and that the acts of 1882 were unconstitutional so far as they had the effect of depriving the taxpayer of his remedy by detinue, or trespass, or case, or other proper action, for unlawful seizure of his goods after tendering tax-receivable coupons in payment of his taxes. McGahey v. Virginia, 135 U. S. 662, 675, 676. But this was far from deciding that the remedy for recovery back would not have been sufficient if the validity of the tax had alone been in issue. The question related to the previous contract that the coupons should be receivable for taxes, which contract the subsequent legislation impaired, and its disposition did not involve the application of the act of 1882, under the circumstances existing here. And while an unconstitutional tax may, in the language of the learned judge holding the Circuit Court, confer no right, impose no duty and support no obligation, it will be perceived that, in our view, the trespass resulting from proceedings to collect such void tax cannot be restrained by injunction where irreparable injury or other ground for equitable interposition is not shown to exist. We are constrained to hold upon this record that the decree cannot be sustained, and it is therefore Reversed and the cause remanded to the court below with a direction to dismiss the bill. MR. JUSTICE HARLAN dissented. Statement of the Case. WESTERN ELECTRIC COMPANY v. LARUE. APPEAL FROM THE CIRCUIT COURT OF THE UNITED STATES FOR THE SOUTHERN DISTRICT OF NEW YORK. No. 279. Argued April 1, 1891.- Decided April 13, 1891. A telegraph sounder constructed under letters patent No. 352,317, granted November 9, 1886, to Charles D. Haskins, infringes the third claim of letters patent No. 270,767 for a new and useful improvement in telegraph keys, viz., The combination, in a telegraph key, of the lever fulcrumed upon the torsional spring, with the adjusting screws H H', for regulating the amplitude of the lever movement and the retractile resistance of the torsion-spring, substantially as described." While the promotion of an old device, such, for instance, as a torsional spring, to a new sphere of action, in which it performs a new function, involves invention, the transfer or adaptation of the same device to a similar sphere of action, where it performs substantially the same function, does not involve invention. Winans v. Denmead, 15 How. 330, affirmed and applied. THIS was a bill in equity brought by LaRue, plaintiff in the court below, for the infringement of letters patent No. 270,767, issued to Edgar A. Edwards, January 16, 1883, for a new and useful improvement in telegraph keys. In the specification the patentee stated that his invention. related "to telegraph keys or instruments used for transmitting telegraphic signals, and is an improvement on the wellknown Morse key, being in substituting for the trunnions or pivots upon which the lever vibrates a torsional spring or strip of metal." After describing the mechanism, as illustrated by his drawings, he made a further statement, as follows: "When a telegraph key is constructed as herein described, the side or lateral movement is reduced to a minimum. The adjustment of trunnion set screws is obviated. The torsional metal springs will not wear out, but last indefinitely. The adjusting screws H H' serve the purpose of regulating the amplitude of the lever movement, and also serve the purpose of regulating the retractile resistance of the torsion-spring. By this arrangement a secondary retractile spring to resist the downward |