LEHMAN, J.
The plaintiff was injured by the fall of a board while she was walking under a shed then being built,by the defendant Chesebro-Whitman Company to protect pedestrians in front of a building in course of erection. , , .
[1-3] To make out her cause of action plaintiff, of course, was bound to prove both that thé defendant was negligent and that she was free from contributory-negligence. The fall of the board, under the circumstances disclosed, was sufficient to raise a presumption of negligence on the part of the defendant; but, even if the defendant was negligent, the plaintiff cannot recover if, in view of her knowledge of the conditions surrounding the work, she failed to exercise a reasonable degree of care in walking under the shed in course of erection. While undoubtedly the defendant was obliged upon the issue of its own negligence to rebut the presumption arising- from the circumstances in which the accident occurred, it was not obliged to show affirmatively that the plaintiff was not free from contributory negligence.
The trial justice, however, charged the jury that the rule of res ipsa loquitur applies here, “so that the plaintiff in this action is not compelled in the first instance to show you that she was free from contributory negligence, but need present only the manner of the occurrence, and, doing so, the law presumes it could only have occurred by an act of negligence on the defendant’s part, and requires that it explain to you how the thing happened in order to rid itself of the charge made.” The court further refused to charge “that the plaintiff is bound to prove by the preponderance of evidence that she herself was free from contributory negligence before she can recover,” and stated that, “if there was any possibility of contributory negligence in what is known as the doctrine of res ipsa loquitur, there would be no force in that doctrine.”
[4] The courts have frequently stated that the rule of res ipsa loquitur means merely that, where the .circumstances of an accident *1076are such that logically and naturally the inference arises that the accident could not have occurred except through the defendant’s negligence, the plaintiff is not bound to prove the exact manner in which the accident occurred, but the defendant is bound to show circumstances which rebut the presumption of his negligence. The circumstances in which an accident occurred may, however, be sufficient to raise, as in this case, the presumption that the defendant-was guilty of negligence, and yet permit the inference that, if the plaintiff has not also been guilty of negligence, she would not have received the-injury. It was the duty of the trial judge to charge the jury in this case that they must first find that the plaintiff was free from negligence in walking under the shed under the circumstances disclosed before they could hold the defendant liable for the negligence which would be inferred from the fall of the board.
Judgment should be reversed, and a new trial ordered, with costs to appellant to abide the event. All concur.