Evans, J.
(After stating the facts.) The objections to the plaintiff’s petition raised by the defendant company’s demurrer were, (1) that it was immaterial whether one of its conductors had or had not given to him the Canadian coin which he tendered to the conductor of the car which he boarded for the purpose of returning to the center of the city; (2) that the facts recited were not such as to render the company liable to the plaintiff as a passenger for the abusive treatment of its conductor in charging him with endeavoring to pass a counterfeit coin; and (3) that the company could not be held legally responsible for the act of the conductor in placing the plaintiff under arrest, the petition not alleging that the "defendant company authorized said arrest or had any part in having the same made.” The right of the plaintiff to recover upon proof of the allegations made in his petition was adjudicated favorably to him by the judgment overruling the demurrer. " Until duly set aside, that decision is conclusive, and the question thereby settled is to be regarded as res adjudicata.” *645Hollis v. Nelms, 115 Ga. 7. In this judgment the defendaut company acquiesced, neither filing exceptions pendente lite nor- bringing it under review by a direct bill of exceptions to this court. Oh the trial of the case, therefore, the only question for determination was the amount of the damages suffered by the plaintiff, in the event he sustained by proof the -allegations of fact on which he based his right of recovery. Richmond Hosiery Mills v. W. U. Tel. Co., 123 Ga. 216. The defendant company was precluded from calling into question the right of the plaintiff to recover upon such proof being made. Ga. Northern Ry. Co. v. Hutchins, 119 Ga. 504. As was remarked by Mr. Justice Cobb in Kelly v. Strouse, 116 Ga. 891-892, “If the defendant calls in question the sufficiency of the petition by demurrer, as he has a right to do, and the court renders an erroneous decision holding that the petition sets forth a cause of action, when in truth it does not, and the defendant acquiesces in this decision, of course no one will contend that, after the time allowed by law has expired for bringing under review this erroneous decision, the defendant can be heard to say that the petition sets forth no cause of action.” When a case is in limine, the trial judge' may of his own motion interpose to prevent a miscarriage of justice, provided “ there is no estoppel of which either party may take advantage.” Ibid. 874. But it is not within the power of the trial judge to give to either party the benefit of a contention which he is himself estopped to urge. Thus, in McCandless v. Conley, 115 Ga. 48, it was held that “Where an amendment to pleadings has been, in term, duly allowed, it is not, after the term has expired, within the power of the court to revoke the order of allowance and strike the amendment on the ground that it was in the first instance erroneously allowed.” During the term of the court at which a judgment is rendered, it is within the breast of the presiding judge and may be vacated upon proper cause .shown; but after the term has expired, the judgment “is upon the roll” and is not subject to review or revision by the trial court. 1 Black, Judg. § 157.
Applying to the present case the well-settled principles of law above stated, we are of the opinion that the court erred in not granting the plaintiff a new trial. The plaintiff presented a written request to charge to the effect that if one of the company’s *646conductors gave to the plaintiff the Canadian coin which he tendered as fare, the conductor to whom it was offered was bound to accept it as legal tender. The judge declined to charge as requested ; and instructed the jury that if the plaintiff did not enter the incoming car of the defendant company prepared to pay his fare in lawful currency of-the United States, he would not occupy the position of a passenger. The jury were further instructed, in effect, that the company could not be held liable in damages for the act of its conductor in placing the plaintiff under arrest, unless the conductor was acting within the scope of the authority expressly conferred upon him by the company and it was contemplated by his master that he should make such an arrest. The court declined to give a charge requested in writing by the plaintiff’s counsel, in which the proposition was stated that if the conductor took hold of the plaintiff and turned him over to a policeman while engaged in the performance of the company’s business and in the line of his duty, because of the non-payment of fare and because he refused to accept the Canadian coin as fare, then the company would be responsible for the conduct of its conductor. The requests to charge were in accord with the theory of liability upon which the plaintiff’s petition was framed; the instructions which the court gave to the jury practically precluded the plaintiff from a recovery under the evidence submitted. Irrespective of whether or not the plaintiff’s petition set forth a cause of action, he was, as the court had adjudged in passing on the company’s demurrer, entitled to damages upon making proof of the allegations of fact upon which he relied for a recovery. It was not within the power of the trial judge to review his ruling upon the demurrer, or, by indirection, give the company the benefit of a defense which it had thereby urged, since it had acquiesced in the decision of the court that there was no merit in any of the objections to the petition which the company urged by way of demurrer. The court did not err in refusing to allow the plaintiff to prove the value of the' Canadian coin which he tendered as fare. Its value, if any it had, was immaterial, even upon his theory of the case, as he took the position that the company was responsible for his having no other money with which to pay his fare, and therefore could not set up the defense that he was not prepared to pay his fare in lawful *647currency of the United States. As to the right of the plaintiff to recover, irrespective of the judgment rendered on the demurrer to his petition, we express no opinion. The important fact is that this question is res adjudicata, as the plaintiff insisted in his motion for a new trial.
Judgment reversed.
All the Justices concur, except Simmons, C. J, absent.