delivered the opinion of the court.

This is an application' by the petitioner for mandamus against Judges Holt and Hough of the District Court of the United States for the Southern District of New. York and the *13 District Court of that district, commanding them and each of them to dismiss all proceedings in bankruptcy against the''New York Tunnel Company, or, in the alternative, to reopen the adjudication in bankruptcy and allow the petitioner or any party in interest to appear 'and be heard in opposition to the petition and adjudication thereof-; or, in still further alternative, forbidding them from taking any further proceedings in the matter of the tunnel company, its property, assets and effects.

The facts, briefly stated,',are that the tunnel company was engaged in constructing a tunnel from New York to .Brooklyn, to be used for the purpose of a railroad between the boroughs of Manhattan and Brooklyn. . On May 23, 1907, certain creditors of the tunnel company filed a petition in bankruptcy in the District Court of the Southern District of New York, upon which petition,.on May 29,1907, Judge Holt entered an order -adjudicating it’ a- bankrupt, and appointing a receiver. ' By direction of the bankruptcy court the .receiver proceeded -with the construction of the tunnel, and successfully completed the work. 'At the time of the petition in bankruptcy this applicant had an action pending in the State court to recover damages on account' of the death of her husband, resulting, as charged, from the negligence of the tunnel company. On May 31,1907, Judge Holt issued an_order to show cause why that action should not be 'restrained, and proof Of the- claim be made before a special master. Ah order of restraint was granted upon this application, which was'afterwards set aside by the Court of Appeals, and the applicant, on' May 25, 1908, reduced her claim to judgment. .

. It is contended bj^ the applicant that although the/petition in bankruptcy alleged that the tunnel-company wa.s “engaged in the business of building and-contracting,” it failed to show' th'at the principal business.-of the company was “trading, printing, publishing, mining, manufacturing. or a mercantile pursuit,” that being the language of. the bankruptcy act of 1898, ás amended.

*14 We have recently given full consideration to the circumstances under which mandamus will be issued by this court to restrain the action of inferior tribunals. In re Winn, 213 U. S. 458. Hence we deem it unnecessary to go into other details of the proceedings in the bankruptcy or the state courts, nor to consider the many questions fully and elaborately presented in briefs and argued by counsel. Obviously, this application is largely in the nature of a writ of error to review the action of the District Court of the Southern District of New York and its judges, and a writ of mandamus is no proper substitute for a writ of error.

The allegation in the petition in bankruptcy is general in its terms that the tunnel company is engaged in the business of. building and contracting, but it fails to disclose the particular kind of work for which it is contracting or which .it is engaged in building. It might be inferred from the work which it was shown it was doing in this particular case, as well as from its name, that its principal business was that of contracting for the construction of tunnels, but that would be only an inference and not conclusive. Its principal business may have been that of manufacturing and contracting for such manufacturing, and this particular work only a small part of that which it was generally engaged in. What evidence was presented to the District Court to sustain the application for an adjudication in bankruptcy is not disclosed. We may not assume that it was insufficient or that it failed to make certain or probable that the principal business of the company wás that of manufacturing and contracting for such manufacturing. We do not deem it necessary to decide the question which is argued by counsel, whether the adjudication of the bankruptcy court can be challenged collaterally or whether indeed this is only a collateral attack. Manson v. Williams, 213 U. S. 453. We rest our conclusion upon the proposition that the' District-Court in adjudicating the tunnel company a bankrupt was called upon to decide, and did decide, a question of fact or of mixed law and fact, and that such adjudication cannot be re *15 viewed by proceedings in mandamus. In re Pollitz, 206. U. S. 323, 331; In re Winn, 213 U. S. 458.

The rule is discharged and the writ of mandamus denied.