This case has once before been considered by this court, (see 146 Mass. 182,) and on the testimony then presented it was not easy to determine, as it is not now, upon slightly different testimony, whether there was any evidence of negligence on the part of the defendant. The only negligence alleged is the failure to warn the plaintiff of the dangers to which he was subjected in doing his work.
An employer is under no obligation to wai’n an employee of dangers which are obvious, nor to instruct him in matters which he may fairly be supposed thoroughly to understand. Nor is it the duty of the master to admonish his servant to be careful, when the servant well knows his danger and the importance of using care to avoid it. It is the duty of the servant to exercise care proportionate to the danger of his situation as he understands it, and if he fails to do so the fault is his and not his master’s. But where the work of a servant exposes him to danger of which he is ignorant, and which, from youth or inexperience, he is manifestly incapable of comprehending *156without assistance, it is the duty of his master, if he knows or ought to know of it, to give him such warning and instruction as are necessary for his safety. In determining the master’s duty in such a case, the inquiry is, What instruction does the servant appear to need? is there reason to believe him ignorant of anything which, for his protection, he ought to know, or incapable of appreciating the risks from what he sees around him ? In the absence of anything to show the contrary, the master has a right to assume that he knows those facts of common experience with which ordinary persons of his age and appearance are familiar. In hiring a boy twelve years of age and apparently of average intelligence, an employer is not called upon to tell him that, if he holds his hand in fire, it will be burned, or strikes it with a sharp instrument, it will be cut, or thrusts it between the teeth of revolving cog-wheels in the gearing of a mill, it will be crushed. From infancy and through childhood, as well as in later life, we are all making observations and experiments with material substances, and every person of ordinary faculties acquires knowledge at an early age of those familiar facts which force themselves on our attention through our senses.
There is nothing in this case to warrant a jury in finding the defendant negligent in omitting to tell the plaintiff that there were cog-wheels on the gig, or that the machinery would injure him if he allowed his hand or arm to get into the gearing, or in failing to repeat a warning which had once been given, or to inform him of risks which he understood himself. Williams v. Churchill, 137 Mass. 243. Russell v. Tillotson, 140 Mass. 201. Crowley v. Pacific Mills, 148 Mass. 228. Buckley v. Gutta Percha & Rubber Manuf. Co. 113 N. Y. 540. But the case presents itself in an aspect somewhat different from that which it wore at the former hearing. Besides some difference in the details of the testimony at the last trial, evidence was introduced from numerous witnesses, which, though contradicted, would warrant a jury in finding that the plaintiff was a boy of less than the average intelligence of boys of his age, and that the defendant knew it, or from his appearance ought to have known it, before the accident. There was additional evidence that the place where he was injured was dimly *157lighted. The undisputed testimony at the former trial tended to show that he possessed at least the intelligence usual in boys of his age, and that fact was referred to in the opinion as one of the grounds of the decision.
It now appears that, while he had worked for a considerable time in the room where the gearing was plainly visible, so that he was undoubtedly familiar with it in a general way, he had never worked so near it as to have occasion specially to consider the risk of getting his clothing caught in it, or the danger of being drawn into it and seriously injured, if some loose part of one of his garments should come in contact with it. There was evidence that a sleeve of his jacket was caught, and that his arm was thus drawn between the wheels. It seems to have been his duty to obey the overseer, who, as he testifies, told him to pick up the punch. The work took him to a place where he had never had occasion to work beforethe order was imperative, calling for haste. He had had no instruction, and it is not clear that he had had any observation or experience, which showed the danger that, in getting down and looking under the machine and getting up again, some part of his clothing might come in contact with the gearing and be caught, and draw his hand or arm between the wheels.
On the whole, we are of opinion that there was some evidence to submit to the jury on the question whether the plaintiff was not obviously in need of information as to this risk. On similar grounds, the plaintiff was allowed to go to the jury, and receive a verdict, in Coombs v. New Bedford Cordage Co. 102 Mass. 572. See also Wheeler v. Wason Manuf. Co. 135 Mass. 294; Glover v. Dwight Manuf. Co. 148 Mass. 22; Swoboda v. Ward, 40 Mich. 420; Huizega v. Cutler Savidge Lumber Co. 51 Mich. 272; Dowling v. Allen, 74 Misso. 13.
There was evidence for the jury upon the question whether the plaintiff was in the exercise of due care.
Judgment on the verdict.