Braley, J.
In Regan v. Lombard, 181 Mass. 329, it was decided that this action could not be maintained at common law, but whether the plaintiff could recover on the count under St. 1887, c. 270, § 1, cl. 2, was not determined. At the second trial the plaintiff relied solely on this count, which alleged that he was injured by reason of the negligence of some person entrusted by the defendants with the duty of superintendence, and who at the time of the accident was engaged in the performance of this duty. Assuming, without deciding, that there was evidence from which the jury could have found that Hanlon was a superintendent within the meaning of the statute; that the curbstones were improperly and insecurely piled, or the dunnage between them either originally was unstable, or had become rotten and unsound, and that in the exercise of reasonable diligence the superintendent should have known of these conditions which might render it unsafe and dangerous for the plaintiff to assist in removing them, yet he cannot recover if at the time of the accident he was guilty of contributory negligence. Fitzgerald v. Connecticut River Paper Co. 155 Mass. 155. O'Maley y. South Boston Gas Light Co. 158 Mass. 135. Wagner v. Boston Elevated Railway, 188 Mass. 437. The stones, when placed, consisted of two circular tiers open at one end, and so arranged that between the inner and outer circles there was a space, into which the plaintiff and other employees went when the stones were to be removed by means of a derrick, the boom of which when lowered for either tier described in its movement the circumference of each circle. As the stones of each tier were piled, when necessary they were adjusted by wooden blocks of different lengths, which kept them separate and rendered' the completed pile level and stable. When needed they were raised from their position by the derrick, and lowered upon a dray, and by these removals the height of the tiers varied.
It was the undisputed evidence of the plaintiff that he had been in the employment of the defendants for many years, during which he had assisted in other yards belonging to the defendants in piling and placing similar stones by the method described, and that, although while working in this yard for a considerable time before the accident he did not assist on the tier which fell, yet the tiers in the different yards were sup*323ported substantially in the same way and he was familiar with the process used. In describing this process he further said that it was the duty of those who piled to chink the stones by the use of dunnage, which consisted of such refuse wood as could be picked up on the premises. After being placed the arrangement of the stones which fell involved no complexity of design such as may arise in the adjustment of ways, works and machinery to adapt them to the purposes of a manufacturing establishment where the mechanism employed or the hazard arising from its use is such as not to be fully understood by the inexperienced employee, or where for the first time a servant is directed by his employer, or by those who properly represent him, to use an instrumentality which is defective, and the defect is or should have been known to them, but is unknown to him. In such cases the servant properly may rely upon the presumption that he will not be directed to put himself in a situation where he may be exposed to the chance of physical injury, or called upon to perform his work by using unsafe appliances. Connolly v. Waltham, 156 Mass. 368. Cunningham v. Atlas Tack Co. 187 Mass. 51. Feeney v. York Manuf. Co. 189 Mass. 336. If it could have been found that the accident was caused by the improper piling, or the decayed dunnage which gave way, thus permitting the stones to lose their balance, and to slide or fall upon him, and that the defendants or their representatives should have known and notified the plaintiff of this possible danger, even then he would not have been put in possession of any facts of which he was ignorant, or with which by the use of ordinary care he could not have made himself acquainted. From his former experience he had become familiar with the general character of the dunnage used as well as the proper manner of setting the stones in place, and as a person of ordinary intelligence must have been aware that, if the dunnage was rotten or the stones improperly put in position, the structure, or a part of it, when disturbed, might be rendered unstable and some of the stones fall. Moreover, he testified that when he entered between the tiers his opportunity for observation was unobstructed, and equal to that of anybody, for their general character was plainly visible. Any warning from the superintendent, that if the dunnage was rotten or the stones had become *324unplaced they might fall, would have conveyed to him no information of which he did not have already, and the failure to apprise him of an obvious danger, which under the circumstances he either knew or must be held to have known to be present, does not constitute a breach of duty by the superintendent while so acting, and therefore a verdict for the defendants was rightly ordered. Downey v. Sawyer, 157 Mass. 418. Goodes v. Boston & Albany Railroad, 162 Mass. 287. Lamson v. American Axe & Tool Co. 177 Mass. 144. Meehan v. Holyoke Street Railway, 186 Mass. 511.
Exceptions overruled.