delivered the opinion of the court.

This was a bill of review, to which a demurrer was interposed by the defendant in the Chancery Court where it was filed; and, after hearing, the bill was dismissed. The decree of the Chancellor was then reversed by the Supreme Court- of the State, the demurrer was disallowed, and, without ny permission given to the defendant to answer, the decree in the original suit, which the bill sought to have reviewed, was vacated and annulled. The court then proceeded to decree against the *435 defendant Bfeard'on the original cause of action, and remanded, the case to the' .Chancery Court for' an; account. An account was accordingly ordered in. that, court, and a final' decree was entered against the defendant, and: subsequently affirmed by the Supreme Court. It is • to .this action .that the present writ of error,'has been sued out.

We have not before us the record of the Original suit, which-was instituted in 1865;' and in which a final decree.- against the plaintiff was made Nov.- 27, 1868. All we eaq? know of it is-what we learn from the bill of review. From that it appears to have been a bill for an injunction against trespass and cutting-wood upon the plain tiff? s land, and for an. account off what had already been. cut. The defendant answered, admitting that he had cut one hundred' and fifty-five and one-third cords-of wood, and setting* up in justification “ that he cut it as an authorized agent of the - gov eminent of the 'United States, and for military purposes, and under the direction and authority, of' the military authorities'.” In- further 'answer, he averred" “that he was protected by-the;order of-the Secretary-of War and the commanding general of Tennessee.” .

In still further answer, he pleaded' that he had a right to; cut ;wood- on the land, as appeared by an order, or authority from; one D. V.. Brown, wood agent of.the- United States;military railroads, and directed to- him, authorizing him.'to cut wood on .said land, as follows :

“ Knoxville, Tenn., May 9,1865.

“James S. Beard is hereby authorized to cut wood for the-U. S. M. R. on the lands of Joseph Burts,.John Lyle, Dillard- Love; by-order of the superintendent.

“D. V. Brown, Wood Agent?

(. To this answer no replication appears to have been filed; but? evidence was submitted, and, after hearing, the Chancellor, found' that Bfeards plea of justification under the laws of the United States, and; by military authority ¿xercised thereunder, was sus-, tained, and that he had acted in pursuance to such-military authority. The plaintiff’s, bill 'was, -therefore, dismissed, and-ho' appeal' was- perfected.

So-much is set- f wth, in the bill of? review, in' which it is also' alleged that- there.vas errot in the original decreed. 'That; *436 assigned, and the only one that requires notice, is that the pretended authority from D. V. Brown, wood agent, was void, and gave the defendant no authority to cut the wood, as there was no order from the commanding general of the department or Secretary of War authorizing the same, nor any act of Congress authorizing the trespass at -the time and place when and where committed.

Such was. the case as presented to the Chancellor, by the demurrer to the bill, and such was the case submitted to the Supreme Court on the appeal taken from the Chancellor’s decree dismissing it.

It is obvious the only important inquiry respects the. validity of the authority- under which the defendant had 'acted. It elaimed to be a privilege or immunity under the laws of the United States. It was found to be authentic by the Chancellor in his original decree, and its authenticity is not denied in the bill of review. That, therefore, is not open to debate. To sustain a bill of review, there must be errors of law appareiit on the face of the decree; or some new matters of fact material in themselves, and discovered after the rendition of the decree.This is. the general rule in equity, and it is the rule .in Tennessee, declared to be such in the present case. The facts are not open for a re-trial, unless the bill asserts that new evidence has been discovered, not obtainable before the first trial by the exercise of reasonable diligence. The conclusions of fact of the court or Chancellor are conclusive. In view of what the, Chancellor found in the original case, it would seem, therefore, •his Conclusion, that the defendant.in cutting the wood was acting under authority from the military authorities, could not be reviewed and set aside. It was a conclusion of fact, deduced from evidence he had before him. . But the Supreme- Court, , while admitting that the original decree could not be said to contain error of law upon its face, took the position that the pleadings in the original cause might be looked to; and, if the conclusions'drawn from admitted facts showed error in law, a bill of review would lie. Accordingly, the court assumed that the paper, signed ‘.D. V. Brown, wood agent,” was all the evidence from which the Chancery Court concluded that the defendant acted under the authority or warrant of the military authorities *437 of the government provided for by the act of Congress, and held that' evidence insufficient and not a justification. For this reason the decree of. the Chancery Court dismissing the bill of review was reversed, and so, also, was the decree dismissing the original bill.

We think this was "an error. The act of Congress of May 11, 1866, 14 Stat 46,- enacted that any acts done or omitted to be done during the rebellion by any person under and by virtue of any order, written or verbal, general or special, issued by the- President, or Secretary of War, or by any military officer of the United States holding the command of the department, •district, or place where such acts are done or omitted, shall, for the purposes of defence, come within the purview of the act of March 3, 1863.- 12,id. 756. The fourth section of the latter act-made the order of. the President, or under his authority,-a defence in all courts to any action for acts done or omitted to be done under or by virtue of such order, or under color of any law of Congress. And the second section of the act of 1866 enacted that, when the order is in writing, it shall be sufficient to produce in evidence the original, with proof of its authenticity, or a certified copy thereof, or, if sent by telegraph, the production of the telegram purporting to emanate from such military officer shall be prima facie, evidence of its authenticity, or, if the original of such order or- telegram is lost, or cannot ■be produced, secondary evidence thereof shall be admissible, as in other cases.

Now, that the defendant’s cutting the wood was under such an order, was, as we have seen, distinctly found as a fact by the Chancellor, and nothing in his decree shows that he found it on the evidence of the paper signed “D. Y. Brown, wood-agent,” alone. No assumption that he did can be justified; and,- if it could be, the order, we think,'was prima fade sufficient. It purported to have been issued by a wood agent for military uses, namely, for the use of the military-railr'oads; and the wood cut was received by the military authorities. It is a legitimate presumption that agents who act for and on behalf of an army in the field are acting under the authority of-its commander; and it is but just to thedearned court to say that it made no attempt to review the finding-'of the authenticity of the'■Brown' *438 paper. They confined their review very properly- to inquiring what was the meaning of the .order, and they held.it no justiiiication of the defendant .because its terms were .riot compulsory, .but -.only permissive.. Their language was, “ There can- be no .pretence, upon the facts set forth in the pleadings,’that any .such thing as military compulsion existed in the case, for the .paper .'only imports on its face' a permission to do .the act compláined.of; ” adding, “.and even this is not license,to do it emanating .from .any recognized’ military authority.” Hence, .said the -.court, “.we conclude that there is .error.of law in the con .elusion of the Chancellor upon the facts.”

If in saying the order or;, permission or license did not emanate from ’-jmy recognized military authority, the court meant to be understood as itself finding a fact, the determination is ¡a .finding-without evidence, .and in opposition to a finding made »on evidence confessedly conclusive, But probably the .court did not -intend'to be - so understood.

The real "question involved, and the only one the court could consider,in the case, therefore,, was whether the -paper was in•effective .as a defence merely because it was in form permissive .'•only. And -upon this question we are unable to concur in (©pinion with the ¿Supreme Court of the State. '- While .it may be conceded that permission to do .an act is not, .compulsion,, .. -and that >the .acts of March 3, 1863, and May 11, 1866, afford ' aio protection to those .acting voluntarily and for their -own benefit, the pleadings show this to have been no such case. The wood was cut for the military railroads, under military (authority, and it was received by,the military authorities before ¡military-operations in -suppression .of tpe rebellion bad ceased. The form of the order we Tegard as immaterial; . -The-plain -purpose of the acts of Congress was to-extend protection, to all - .persons who might act in subordination to tbe -military .authorities^ engaged in conducting' the war. Congress púrposed, we ..think, to confer upon-them the same exemption from liability to suit whicb belonged to-the President, the Secretary of War,-' -and the' department, commanders. • The- orders of ' which, the ,aets_. speak are military .orders, and a large. proportion of such orders, it is well known, are .merely permissive in form'. They necessarily leave much to the discretion of those to whom they *439 are addressed. We cannot doubt that Congress bad sucb orders in view, and that its action was intended to protect against civil suits those who might do acts either commanded or authorized by them.

The decree of the Supreme Court of Tennessee must, therefore, be reversed, and the record remitted with instructions to reverse the last decree of the Chancellor, and direct him to dismiss the bill of review; and it is So ordered.