delivered the opinion of the Court:
We are not called upon to determine the validity of the entry of Godsmark, or whether it gave him a right to an additional entry which petitioner, by purchase, could exercise. The authority is vested in the Secretary of the Interior by Congress, to examine into and pass upon the validity of applications to enter the public lands of the United States. His decision in 'this instance not only involved the exercise of judgment and discretion, but was made in the discharge of a duty imposed by law. To grant the petition would require us not only to review the decision of the Secretary, but to determine matters essential to petitioner’s right to make the entry, which have not, so far as the record discloses, been passed upon by the Secretary. Assuming that Godsmark did make a valid original homestead entry, before petitioner’s application should be allowed the Department would have to investigate his military record, whether he had in fact assigned his right, and, if so, whether petitioner is the lawful assignee. Hence, we are not only called upon to review the decision of the Secretary, but *9to exercise original jurisdiction as to the determination of the above facts in a matter in which he is vested with exclusive jurisdiction. Mandamus will not afford the petitioner any relief. The writ cannot be made to perform the function of a writ of error, and is not therefore available for the purpose of compelling the head of a department of the government to reverse a decision made in the exercise of the judgment and discretion reposed in him by law, and which he had full jurisdiction to make. Neither will it issue to control the judgment and discretion of an officer in the decision of a matter which the law imposes upon him the duty of originally deciding for himself. Decatur v. Paulding, 14 Pet. 497, 515, 10 L. ed. 559, 568; United States ex rel. Tucker v. Seaman, 17 How. 225, 230, 15 L. ed. 226, 227; Gaines v. Thompson, 7 Wall. 347, 19 L. ed. 62; Litchfield v. The Register (Litchfield v. Richards) 9 Wall. 575, 19 L. ed. 681; United States v. Schurz, 102 U. S. 378, 26 L. ed. 167; United States ex rel. Dunlap v. Black, 128 U. S. 40, 48, 32 L. ed. 354, 357, 9 Sup. Ct. Rep. 12; United States ex rel. Riverside Oil Co. v. Hitchcock, 190 U. S. 316, 324, 47 L. ed. 1074, 1078, 23 Sup. Ct. Rep. 698; United States ex rel. Ness v. Fisher, 223 U. S. 683, 56 L. ed. 610, 32 Sup. Ct. Rep. 356.
The question of law suggested is not a new one, and origina] discussion is unnecessary in the light of the above decisions. The action of the Secretary was neither arbitrary nor merely ministerial, but was taken in the exercise of judgment and discretion within the authority conferred by law. It cannot therefore be controlled by mandamus.
The judgment is affirmed, with costs, and it is so ordered,
Affirmed.
On May 14, 1912, an application by the appellant for the allowance of a writ of error from the Supreme Court of the United States was denied.