was to be paid, they made a separate assessment on all property at a valuation of one hundred per cent.

In the Chancery Court the defendants contested the validity of the assessment, and judgment was entered for only one-half of the tax assessed against them for general county purposes. On appeal, the Supreme Court of Arkansas held that no tax could be lawfully assessed for those purposes upon a valuation in excess of the fifty per cent. valuation on which the assessment for other taxing purposes was based, and affirmed the judgment below. 162 Ark. 443.

The plaintiff in error invokes the jurisdiction of this Court under Judicial Code, § 237, alleging that the Supreme Court of Arkansas has drawn in question the validity of an authority exercised under the United States and has decided against its validity, in refusing to enforce the collection of overdue taxes upon an assessment ordered by the federal court; and assigns as error that in so doing the state court has refused to give effect to the judgment and mandamus of the District Court, in contravention of the judicial power granted to the federal courts by Article 3 of the Constitution, and Acts of Congress pursuant to it, and in contravention of Clause 2 of Article 6 (making the Constitution and laws of the United States the supreme law of the land).

In holding invalid the assessment as made for general county purposes, the Supreme Court of Arkansas disclaimed any purpose to attack collaterally the judgment of the United States District Court, or to deny its full force and effect as rendered. It rested its decision on the narrow ground that the assessment upon the property of defendants in error was not made on a valuation uniform within Craighead County for all purposes of taxation, state, county, municipal and school, as required by the state constitution (Article 16, § 5; Hays v. Missouri Pacific R. R. Co., 159 Ark. 101), and that as made the

assessment did not comply with the judgment of mandamus which specifically required the tax officials to assess at full value all property in Craighead County. Since the court deemed that the assessment complied neither with the requirements of the constitution nor with the directions of the judgment of the District Court, it held that there was no denial of the authority of the judgment in holding the assessment invalid under the state constitution.

If the mandamus order had in terms directed the assessment to be made as it was in fact made by the taxing officials, or if the assessment had been held to be invalid on the ground that, although made as directed, it was not uniform with the valuation employed in other counties of the State, questions would have been presented which are not raised by this record. We might then have had to consider whether the determination of the state court did not, in effect, attack collaterally the judgment of the District Court and deny its authority, even though that judgment rested on a different view of the state constitution than that adopted by the Supreme Court of Arkansas. See United States ex rel. v. Jimmerson, 222 Fed. 489, and United States ex rel. v. Cargill, 263 Fed. 856.

These are questions which we are not called upon to decide here; for we find no necessary conflict between the mandamus order of the District Court and the constitution of the State as interpreted and applied to the assessment by the state Supreme Court. The District Court undoubtedly had jurisdiction to compel the assessing officers of the county to levy a tax for the purpose of securing satisfaction of its judgment. Memphis v. Brown, 97 U. S. 300; United States v. Fort Scott, 99 U. S. 152. For that purpose it had jurisdiction to determine what form of assessment would accord with the laws and

the constitution of the State of Arkansas and to prescribe the manner in which the assessments should be levied. Riggs v. Johnson County, 6 Wall. 166; Prout v. Starr, 188 U. S. 537.

But in directing the assessment to be made within the county on the basis of a uniform valuation, the judgment did not specify the mode of assessment for different tax purposes; it did not direct that the assessment at an increased valuation should be made only for county taxation. Being silent with respect to these details, it must be taken to direct an assessment within the county at full valuation, in accordance with the laws of the State, leaving to be determined, by proceedings appropriately had in either the District Court or the state court, the question whether the assessment actually made complied with those laws. No proceedings were had to secure a modification of the judgment of the District Court so that it would direct the assessment to be made in the mode actually employed, or to compel an assessment on a uniform valuation for all tax purposes, on the theory that such uniformity was required by the state law, and in the view, which we adopt, that the judgment required an assessment to be made within the county according to that law.

In that situation we do not find any basis for the contention that the authority of the judgment of the District Court was denied or its validity questioned by the determination of the state court that the assessment as made within the county was invalid. The mandamus not having prescribed the particular method of assessing the tax, the state court was left free to determine whether the assessment was made according to law, and in so doing it did not determine any matter which had been adjudicated by the District Court or refuse to give full effect to its judgment.

The writ of error is

Dismissed for want of jurisdiction.

Statement of the Case.

CONCRETE APPLIANCES COMPANY ET AL. v. GOMERY ET AL.

CERTIORARI TO THE CIRCUIT COURT OF APPEALS FOR THE THIRD CIRCUIT.

No. 44. Argued October 14, 15, 1925. Decided November 16, 1925. 1. Concurrent findings of the District Court and Circuit Court of Appeals against the novelty of a patented device will be reviewed by this Court when a contrary conclusion in respect of the same patent claims has been reached by the Circuit Court of Appeals in another circuit. P. 180.

2. Judicial notice taken, that the principle of conveying and distributing mobile substances by gravity has found exemplification for centuries in apparatus for raising and distributing water. P. 180.

3. In view of the state of the art, patent No. 948,719, (as to claims 1, 2, 5 and 13,) for a combination of apparatus, designed for transferring wet concrete, or other plastic materials, from a source of supply to working points on a building or other structure in course of construction, is void for want of invention; the combination being no more than an application of mechanical skill to known elements, in the course of a natural development of the art. P. 184. 4. The combination comprised: (1) a tower; (2) a boom, oscillatory or swinging horizontally, adjustably connected with the tower and adapted to be arranged at various points in its height; (3) a conduit carried by the boom, extending laterally from the tower, connected to it and adjustable vertically at varying heights in the tower; (4) a means for raising plastic material to the height desired in the tower; and (5) a means for receiving the plastic material from the raising means and conducting it to the conduit, both the raising means and the receiving means being adjustable vertically at varying heights in the tower.

291 Fed. 486, affirmed.

CERTIORARI to a decree of the Circuit Court of Appeals for the Third Circuit which affirmed a decree of the District Court (see 284 Fed. 518) dismissing the bill in a suit to enjoin infringement of the petitioners' patent.

Mr. Stephen J. Cox, with whom Messrs. Arthur M. Hood and Cyrus N. Anderson were on the brief, for petitioners.

Mr. George Bayard Jones, with whom Messrs. Thomas F. Sheridan and William Steell Jackson were on the brief, for respondents.

MR. JUSTICE STONE delivered the opinion of the Court.

In an earlier suit petitioners sought to enjoin an infringement of the Callahan patent, No. 948,719, and the Circuit Court of Appeals for the Sixth Circuit held the patent valid. Concrete Appliance Co. v. Meinken, 262 Fed. 958. Later the present suit was brought in the District Court for the Eastern District of Pennsylvania to enjoin an infringement of the same patent by the respondents. The District Court expressed the opinion that the claims of the patent did not involve invention, but in deference to the determination in the Sixth Circuit, dismissed the petitioners' bill on the ground of noninfringement. 284 Fed. 518. On appeal, the Circuit Court of Appeals for the Third Circuit held that the patent was invalid for want of invention. 291 Fed. 486. In view of the conflict of decision, the writ of certiorari was granted by this Court (264 U. S. 578) to review the determination in the Third Circuit. Thomson Co. v. Ford Motor Co., 265 U. S. 445. Both suits involved claims numbered 1, 2, 5 and 13 of the Callahan Patent for "Material Transferring Apparatus" designed for use in transferring concrete or other plastic materials from a suitable source of supply to working points desired on a building or other structure, in the course of construction.

In principle, the device concerned calls into operation gravity, in conveying mobile substances from an elevated central point to varying working points in building operations. The claims made by the patentee, which relate