The plaintiff knew the permanent elements of the danger to which he was exposed. He knew that the trap doors were where they were, and that they were likely to be opened from time to time. The doors of themselves were not a defect, and he took the risk of them. The only thing he did not know was the precise moment when the doors would be raised, but that he could find out if he looked. They were raised and the accident happened during the noon hour, at which time the plaintiff was not called on to work. A majority of the court are of opinion, although I share the doubts of the minority, that the defendant’s duty did not extend to giving notice or warning that the doors were open to one who knew that they were liable to be so at any time. See Keenan v. Edison Electric Illuminating Co. 159 Mass. 379; McCann v. Kennedy, ante, 23.

Exceptions overruled.