SEVERENS, Circuit Judge,
after having stated the case, deliv ered the opinion of the court.
*229In tlie brief and argument for the appellants it is urged that their rights cannot properly be litigaied upon a mere petition filed by the receiver in a suit to which they are not parties, and that they are entitled to the advantage of making their defense in a formal suit upon an independent bill. When the proceeding is taken by a receiver appointed in a suit to which the proposed defendant is a stranger, the question whether it should be by bill or petition is one resting to a certain extent in the discretion of the court, having regard to the particular circumstances. A leading purpose in determining it will always be io afford the defendant full opportunity to assert and obtain the benefit of his defense. Where, as here, the property concerned is already in the possession of the court, and the act complained of is a disturbance of that possession, it is not unusual to allow the receiver to proceed by petition, giving the defendant: the opportunity of making defense by answer or other pleading, according to the common course of equity practice. This was the practice sanctioned in Ex parte Chamberlain (C. C.) 55 Fed. 704. where the proceeding was taken to prevent the disturbance of the receiver in the possession held by him under the order of the court of certain property upon which the respondent was undertaking to make a tax levy, and In re Tyler, 149 U. S. 164, 13 Sup. Ct. 785, 37 L. Ed. 689, where the respondent, under claim of right, founded upon a state statute, attempted to seize property in the hands of a receiver appointed by the federal circuit court. And see, also, High, Bee. § 777; Beach, Rec. (1st Ed.) § 739. We see no reason for thinking that in the present cast* any right of appellants could have been compromised by the complaint being preferred by a petition rather than by a bill. They have filed an answer in which they set up the only defence which they claim exists, and the common replication has been filed. It remains io produce the proof, and thereupon a final order or decree can he made upon the merits. If there was any reason why their rights could not he fully protected in the proceeding which was instituted, the objection should have been made in the court below. Instead of that, they were content to answer on the merits, submitting to the judgment of the court, without making any suggestion of difficulty or embarrassment. Dior do they raise such a question by the assignments of error, all of which relate solely to the supposed error of I he court Ir. bolding that upon the fads shown an injunction should issue. We think that, if the particular mode of obtaining the remedy was mistaken, the defendants have waived the error.
2. Then it is said that there- was nothing in the petition which showed that there was any reason for apprehending such immediate and special injury as would justify a preliminary injunction. But the petition stated that the defendants, without any right whatever, were running their engines and cars over the track occupied by the receiver in carrying on his railroad business, and “that said companies get access to said track with /heir engines and cars over a connection therewith which it is neeessaiy for your petitioner to ise, so that your petitioner cannot forcibly prevent their said unlaw'ul use of said track without danger to life and property.” It must *230be admitted that the allegation is not so specifically directed to the probability of danger in the running of engines and cars over the track by the defendants as it might have been. But the court was bound to take notice of the mode in which railway business is ordinarily conducted, and hence of the danger to life and property in the continued trespassing by another company with their engines and cars upon the track, which was in daily and probably hourly use of the receiver. Certainly we cannot say that the conclusion of the lower court in that regard was so unwarranted as to justify us in reversing its order. In order to reach that result upon a mere question of fact, the error must be very clear. Thompson v. Nelson, 37 U. S. App. 478, 18 C. C. A. 137, 71 Fed. 339; Proctor & Gamble Co. v. Globe Refining Co., 34 C. C. A. 405, 92 Fed. 357.
3. The case, stated was one within the equitable jurisdiction of the court. The trespasses complained of were of frequent repetition, and would, if continued, give ground for a great multiplicity of suits. Relief in equity by injunction was the only adequate remedy, and it was not necessary to await a trial and judgment at law. Chessman v. Shreve (C. C.) 37 Fed. 36; Joy v. St. Louis, 138 U. S. 1, 11 Sup. Ct. 243, 34 L. Ed. 843; Coatsworth v. Railroad Co., 156 N. Y. 451, 51 N. E. 301; Musselman v. Marquis, 1 Bush, 463.
4. The answer of the defendants admitted that the receiver had acquired from the Baltimore & Ohio Railroad Company the interest in the track which he claimed in his petition to have. But it averred that the defendants had themselves acquired the right to make use of the track complained of by the receiver (the particulars of which are set forth) from the said Baltimore & Ohio Railroad Company prior to the date of the acquisition by the receiver of the right on which he relies. It is insisted for the defendants (and perhaps rightly), that, if the fact is as thus averred, the receiver had no ground on which to support his petition. But the difficulty is that, while this may be good as matter of pleading, the answer is not sworn to by any one who professes to have knowledge of the fact pleaded. The answer, for the purposes of the motion for preliminary injunction, may serve as an affidavit, and has only the same effect. The verification of the answer was by one of the solicitors, who made oath that "the statements of the foregoing answer are true, as he verily believes.” There is no showing, however, that he had made such investigation of the facts as would enable him to speak with assurance, and his qualified statement rather implies that he had not, and there is no extrinsic showing of the contract. It seéms to be settled that such a verification of the answer or of an affidavit is insufficient proof upon the hearing of a motion, either for an injunction, or to dissolve one already granted. Barb. Ch. Prac. 156; 2 High, Inj. 1514, and the cases there cited; Campbell v. Morrison, 7 Paige, 157; Miller v. McDougall, 44 Miss. 682; Spalding v. Keely, 7 Sim. 377. It is true, there is the same infirmity in the receiver’s verification of his petition. But the answer admitted the receiver’s prima facie case, and it then set up, by way of justification, the defendants’ prior right. The burden of proof of this matter thus set up was upon the defendants. Gresley, Eq. Ev. (2d Am. Ed.) 16, 468; Hart v. Ten *231Eyck, 2 Johns. Ch. 62; McCoy v. Rhodes, How. 131, 13 L. Ed. 634; Reid v. McCallister (C. C.) 49 Fed. 16; Jennison, Ch. Prac. 84. The defendants failed to support this burden by any proof sufficient in law. The result is that we find no sufficient reason for disturbing the order of which the appellants complain, and it is accordingly affirmed.