Opinion of the Court. the other hand, the method employed by the defendants consists, first, in subjecting the cleansed surface of the iron to a heat of 480 degrees Fahrenheit, sufficient to change its color by oxidizing, and then applying a coat of copal varnish and heating again to a point not in excess of 300 degrees Fahrenheit, which, while sufficient to harden and color the varnish by what is called the process of oxidation, yet is not sufficient to oxidize the iron itself. It is difficult, if not impossible, to distinguish by the eye the result of this process from Tucker bronze made according to the patents, but the two processes differ in the particulars pointed out; the effect in Tucker bronze appearing to be produced by the joint oxidation of the iron and the oil, while in the defendant's product the result is attained by successive heatings, first of the iron, and then of the iron and oil, the heat, in the second step of the process, not being sufficient to cause a joint oxidation of the iron and the oil. It seems necessarily to follow from this view either that the Tucker patents are void by reason of the anticipation practised by Brocksieper, or that the patented process and product must be restricted to exactly what is described, that is, to a simultaneous and joint oxidation of the iron and the oil after the application of the oil to a cleansed surface of cast iron. To that extent the patents may be sustained, but upon that construction they do not include the process and product of the defendants; there is consequently no infringement. In opposition to this conclusion it is contended, on the part of the appellants, that the witnesses who testify to the methods employed by Brocksieper in 1857 have confounded in their memory the actual facts in regard to that method as then practised with processes subsequently employed, and which could have been learned only after the issue of the Tucker patent in 1863; and in corroboration of that criticism. upon this evidence it is shown that reproductions of the Brocksieper method, made under the eye of the examiner by a competent expert, during the progress of the taking of the testimony, were not distinguishable in appearance from Tucker bronze made according to the patents. We are not, however, VOL. CXX-29 Statement of Facts. able to adopt that view of the evidence. The fact that by careful workmanship the products are indistinguishable by mere inspection does not establish the identity of the processes, and as the patent for the product must be limited to an article made by the particular process, the inquiry must be determined by a comparison between the methods actually employed. As that used by the defendants differs from that described in the patent, just as that employed by Brocksieper does, the process of the defendants cannot be construed as an infringement without at the same time declaring that used by Brocksieper to be an anticipation. The decree of the Circuit Court must, therefore, be Affirmed. ROSENBAUM v. BAUER. ROSENBAUM v. SAN FRANCISCO. ERROR TO THE CIRCUIT COURT OF THE UNITED STATES FOR THE DISTRICT OF CALIFORNIA. Submitted January 17, 1887. Decided March 7, 1887. A Circuit Court of the United States cannot acquire jurisdiction, by removal from a state court, under § 2 of the act of March 3, 1875, c. 137 (18 Stat. 470) of an original proceeding to obtain a mandamus against the treasurer or the board of supervisors of a city, to compel them to take action, in accordance with a statute of the state, to pay the interest or principal of bonds issued by the city. Section 716 of the Revised Statutes, giving power to a Circuit Court to issue all writs not specifically provided for by statute, which may be necessary for the exercise of its jurisdiction, and agreeable to the usages and principles of law, construed in connection with §§ 1 and 2 of the act of 1875, operates to prevent the issuing by the Circuit Court of a writ of mandamus, except in aid of a jurisdiction previously acquired by that court. THESE actions were commenced in a state court of California, were removed thence into the Circuit Court of the United States on the plaintiff's motion, and were remanded to the Opinion of the Court. state court on the defendant's motion. The plaintiff sued out these writs of error. The case is stated in the opinion of the court. Mr. Attorney General and Mr. A. L. Rhodes for plaintiff in error. Mr. Philip G. Galpin and Mr. George Flourney, Jr., for defendants in error. MR. JUSTICE BLATCHFORD delivered the opinion of the court. On the 13th of October, 1885, Albert S. Rosenbaum brought an action in the Superior Court of the city and county of San Francisco, in the State of California, against John A. Bauer, treasurer of the city and county of San Francisco. The complaint set forth the issuing of certain bonds, called Montgomery Avenue bonds, by the Board of Public Works of the city and county of San Francisco, under an act of the legisla ture of California, approved April 1, 1872, Stats. of 1871-2, c. 626, entitled "An act to open and establish a public street in the city and county of San Francisco, to be called 'Montgomery Avenue,' and to take private lands therefor." The act provided for the creation by taxation of a fund for the payment of interest on the bonds, and of a sinking fund for their redemption; and enacted that whenever such treasurer should have in his custody $10,000 or more belonging to the sinking fund, he should advertise for proposals for the surrender and redemption of the bonds. The complaint alleged that the plaintiff owned twenty-one of the bonds of $1000 each; that the treasurer had in his hands over $12,000 belonging to the sinking fund; that the plaintiff had exhibited his bonds to the treasurer and demanded that he advertise for proposals for the surrender of bonds issued under the act; that he refused so to do; and that no part of such bonds had been paid. The complaint prayed for a judgment that the defendant, "as treasurer of the city and county of San Francisco, be commanded to advertise for the redemption of Montgomery Avenue Opinion of the Court. bonds, as in section eleven of the act hereinabove referred to provided." Three days afterwards, the plaintiff filed a petition for the removal of the suit into the Circuit Court of the United States for the District of California, on the ground that the plaintiff was a citizen of New York and the defendant a citizen of California. The state court made an order of removal. The record being filed in the Federal court, the defendant demurred to the complaint, specifying as a ground of demurrer that the Federal court had no jurisdiction of the subject of the action. The case being heard on the demurrer, the court made an order, on the 18th of January, 1886, that the cause be remanded to the state court, "this court having no jurisdiction of this cause in this form." The plaintiff has brought a writ of error to review that order. The same act provided that an annual tax should be levied on the property therein mentioned to raise money to pay the coupons annexed to the bonds, and another annual tax to create a sinking fund for the redemption of the bonds, the taxes to be levied in the manner in which other taxes are levied, that is, by the Board of Supervisors. The same Rosenbaum, being the owner of twenty-one of the bonds, and of eight matured coupons, of $30 each, attached to each bond, each coupon being for six months' interest, the first of them having matured January 1, 1882, brought an action, on the 12th of December, 1885, in the said Superior Court of the city and county of San Francisco, against the Board of Supervisors of the city and county of San Francisco. The complaint set forth that there were no funds in the hands of the treasurer applicable to the payment of any of the coupons; and that the plaintiff had demanded of the Board that it levy a tax sufficient to pay the coupons, but it had refused so to do. The complaint prayed for a judgment "against sald Board of Supervisors, commanding them to levy the tax hereinabove mentioned, and to continue to levy said tax from year to year until all the interest upon said bonds, and said bonds themselves, are fully paid." On the 21st of December, 1885, the plaintiff filed a petition Opinion of the Court. for the removal of this latter suit into the Circuit Court of the United States for the District of California, on the ground of diversity of citizenship in the parties. The state court made an order of removal. The defendant made a motion in the Federal court to remand the case to the state court on the ground of want of jurisdiction by the Federal court "of the subject-matter contained in the complaint." On the 24th of May, 1886, the court made an order granting the motion, and the plaintiff has brought a writ of error to review that order. The Circuit Court, in remanding the causes, 28 Fed. Rep. 223, proceeded on these grounds: (1) That it had always been held by this court that the Circuit Courts had no jurisdiction to award a mandamus except as ancillary to some other proceeding establishing a demand, and reducing it to judgment, the mandamus being in the nature of process for executing the judgment. (2) That a proceeding for a mandamus was not a suit of a civil nature, within the meaning of any provision of the act of March 3, 1875, c. 137, 18 Stat. 470, and was not removable under it. Prior to the act of 1875, it was well settled that the Circuit Courts had no jurisdiction to issue a writ of mandamus in a case like the present. In McIntire v. Wood, in 1813, 7 Cranch, 504, it was held that a Circuit Court had no power to issue a mandamus to the register of a land office of the United States, commanding him to grant a final certificate of purchase to the plaintiff for lands to which he supposed himself entitled under the laws of the United States. In that case, the plaintiff's alleged right to a certificate of purchase was claimed under the laws of the United States, but this court, speaking by Mr. Justice Johnson, said, that the power of the Circuit Courts to issue the writ was confined by 14 of the Judiciary Act of 1789, 1 Stat. 81, to those cases in which it might be necessary to the exercise of their jurisdiction. This provision of § 14 appears now in § 716 of the Revised Statutes in these words: "SEC. 716. The Supreme Court and the Circuit and District Courts shall have power to issue writs of scire facias. They shall also have power to issue all writs not specifically provided for by statute, which may be |