delivered the opinion of the Court:
While it is the duty of a master to provide reasonably safe places in which and structures upon which his servants are to work, he cannot be expected, and is not required, to keep a building which they are employed in erecting “in a safe condition at every moment of their work, so far as its safety depends upon the due performance of that 'work by them and their fellows.” Armour v. Hahn, 111 U. S. 313, 318, 28 L. ed. 440, 441, 4 Sup. Ct. Rep. 433. The plaintiff in that case was a carpenter, and his injury was caused by the giving way of a piece of timber which had been placed in the brick wall of the building in process of construction. The court observed that if, at the time of the accident, this piece of timber was insecure, •it was either by reason of the risks ordinarily incident to the state of things in the unfinished condition of the building, “or else by reason of some negligence of one of the carpenters or bricklayers, all of whom were employed and paid by the same master, and were working in the course of their employment at the same place and time, with an immediate common object, the erection of the building,” and therefore that, “within the strictest limits of the rule of law upon the subject,” they were fellow servants.
In Northern P. R. Co. v. Hambly, 154 U. S. 349, 38 L. ed. 1009, 14 Sup. Ct. Rep. 983, it was held that a day laborer in *559the employ of a railroad company, and under the immediate direction of a section boss or foreman on a culvert of the company’s line of road, was a fellow servant of the conductor and engineer operating a passenger train, and through whose negligence the plaintiff was injured. The court laid down the following test of liability: “If the departments of the two servants are so far separated from each other that the possibility of coming in contact, and hence of incurring danger from the negligent performance of the duties of such other department, could not be said to be within the contemplation of the person injured, the doctrine of fellow service should not apply.” The court further observed that “to hold the principal liable whenever there are gradations of rank between the person receiving and the person causing the injury, or whenever they are employed in different departments of the same general service, would result in frittering away the whole doctrine of fellow service.”
Of course, if an act is done in the discharge of some positive duty of the master to the servant, then negligence in the performance of the act is negligence of the master, notwithstanding that it was performed through another servant. Carter v. McDermott, 29 App. D. C. 145, 10 L.R.A.(N.S.) 1103, 10 Ann. Gas. 601; Collins v. John W. Danforth Co. 36 App. D. C. 592; Thompson-Starrett Co. v. Wilson, 39 App. D. C. 211; Baltimore & O. R. Co. v. Baugh, 149 U. S. 386, 37 L. ed. 780, 13 Sup. Ct. Rep. 914; Northern P. R. Co. v. Herbert, 116 U. S. 647, 29 L. ed. 758, 6 Sup. Ct. Rep. 590.
In the light of the foregoing, we will now examine the facts of the present case, having in mind that the claim of negligence is based solely upon the manner in which the piece of trim in question wras placed in the room Avhere plaintiff Avas to work. Admittedly, this piece of material Avas to be used in the construction of the building. Its position was extremely temporary and transitory. The employee who carried it into the room and the employee who Avas then to Avork upon it were engaged in the same common object, the construction of the building, and their duties were intimately connected. Supposing that the plaintiff had *560been at work shingling a roof for the defendant, and the defendant had detailed another carpenter to take charge of the work of distributing materials with which to do the work, and that one of the workmen, in carrying a bunch of shingles, had carelessly dropped them on the plaintiff, thereby throwing him from the roof and causing him injury, could it be contended that under such a set of facts the plaintiff would be liable ? Or, supposing that Mr. Matthews in the present case, after plaintiff had placed a piece of trim on his trestles, had carelessly knocked it off as he (Matthews) was carrying in another piece, and had thereby caused an injury to plaintiff’s foot, could it reasonably be contended that the common employer would be liable ? The injury in each of those cases clearly would have been caused by the carelessness of a fellow servant, and not by any negligence of the employer. In the present case the employer furnished a proper room, proper materials, and was not negligent in selecting its employees. It directed one set of employees to carry around and conveniently place those materials, and another set of employees, including the plaintiff, to work upon them. We think the conclusion irresistible that the two sets of employees were fellow servants within the rule laid down by the Supreme Court of the United States.
Negligence must be affirmatively established by the employee. Thompson-Starrett Co. v. Warren, 38 App. D. C. 310, 318; Patton v. Texas & P. R. Co. 179 U. S. 658, 663, 45 L. ed. 361, 364, 21 Sup. Ct. Rep. 275. In the present case the evidence tended to show that the piece of trim on the morning of the accident was set up on the floor about a foot from the wall, and that it inclined toward but did not touch the wall. In other words, as observed by the trial court, it had “nothing to support it except its own base.” The evidence is silent as to whether it was placed in a manner different from that in which the other two pieces were placed in the same room. But if this piece was negligently placed, no one was in a better position to appreciate the fact than the plaintiff when he commenced work in the room, lie was a skilled carpenter and, working as he did within a few feet of this trim, could not help observing, if lie paid any atten*561tion to Ills surroundings, how it was placed and appreciating to the fullest extent any danger incident thereto. It was not a complex danger; nor rvas he hurried, as was the plaintiff in Duvall v. Philadelphia, B. & W. R. Co. ante, 395. There was nothing in the room except those pieces of trim, and if this particular piece was placed in an unusual position, that fact should have attracted plaintiff’s attention immediately; and if, on the other hand, the position in which it was placed was the usual one, he certainly knew when he went into the room that it was liable to fall. In either case he must be presumed to have assumed the risk.
The judgment must be affirmed with costs. Affirmed.