“ The court has no general supervisory power over the officers of the Land Department by which to control their decisions upon questions within their jurisdiction. If this writ were granted we would require the Secretary of the Interior to repudiate and disaffirm a decision which he regarded it his duty to make in the exercise of that judgment which is reposed in him by law, and we should require him to come to a determination upon the issues involved directly opposite to that which he had reached, and which the law conferred upon him the jurisdiction to make. ”

“ Mandamus has never been regarded as the proper writ to control the judgment and discretion of an officer as to the decision of a matter which the law gave him the power and imposed upon him the duty to decide for himself. The writ never can be used as a substitute for a writ of error. ”

“ The head of an executive department of the government, in the administration of the various and important concerns of his office, is continually required to exercise judgment and discretion. He must exercise his judgment in expounding the laws and resolutions of Congress, under which he is from time to time required to act. . . . If a suit should come before this court which involved the construction of any of these laws, the court certainly would not be bound to adopt the construction given by the head of a department. ”