It does not appear that the plaintiff did not possess the average intelligence of boys of his age. There was nothing unapparent or complicated about the elevator or its operation. The plaintiff testified that he knew all there was to do with the elevator, and no reason is disclosed why he should not have known it, though he was only fifteen years and four months old at the time of the accident. He knew that Brown was a green hand, and even a boy must know, we think, that green hands are liable to do things which experienced ones would not. The accident appears to have been caused by the manner in which Brown started the elevator, and about which the plaintiff had previously instructed and cautioned him. We do not think that the evidence discloses any negligence on the part of the defendants or their superintendent. Coullard v. Tecumseh Mills, 151 Mass. 85. Henry v. King Philip Mills, 155 Mass. 361.

Exceptions overruled.