Opinion by-

This appeal raises primarily the question of burden of proof. Under the facts proven at the trial, was the burden of proof on the defendant company to show that the injury for which appellant claims damages was in no way the result of its negligence, or was the burden on appellant to establish the negligence of the defendant company. In order to cast this burden on the defendant company it was necessary for appellant to establish that the injury complained of resulted from the breaking of machinery, collision, derailment of cars, or something improper or unsafe in the conduct of the business or in the appliances of transportation: Thomas v. Railroad Company, 148 Pa. 180. This case is also authority for the rule that where a passenger on a railroad train while sitting at the *555window of a car was injured by a missile, the nature and origin of which were unknown, and there was nothing to connect the accident with a defect in any of the appliances of. transportation or any negligence on the part of the company or its employees, there can be no recovery against the company. These principles rule the present case. The evidence produced at the trial was not sufficient to establish the fact that the injury complained of resulted from the breaking of machinery, collision, derailment of cars or anything improper or unsafe in the conduct of the business of the railroad or in the appliances of transportation. The evidence was not sufficient to establish the fact that the accident complained of was the result of the explosion of a torpedo. The case of Ault v. Cowan, 20 Pa. Superior Ct. 616, is in point. In that case the allegation was that the injury had been occasioned by the explosion of a torpedo, and it was held that there can be no recovery unless the plaintiff prove by affirmative evidence that the cause of the explosion was one for which defendant was liable. The only evidence in the present case on the question of the explosion of a torpedo was that of the plaintiff himself who said that immediately before the window was struck he heard two sharp reports like the explosion of a torpedo and that an engine of a train on the track adjoining was just opposite his window, and from these facts the appellant contends that the jury should have been permitted to infer that the accident was occasioned bj^ the explosion of a torpedo. We think the evidence was not sufficient for this purpose. At most it was a mere guess or conjecture, and something more definite must be established as the foundation of an action for damages.

Judgment affirmed.