In our opinion the falling of the buffer was under the circumstances in itself evidence of negligence. This disposes of the fifth request and also of the request that the jury be directed to find for the defendant. Although the plaintiff in his evidence went beyond showing that the buffer fell, he did not go far enough to deprive him of the case made by the falling of the buffer. The case in this respect comes within Cassady v. Old Colony Street Railway, 184 Mass. 156.

*504Taking the instruction as a whole, it is not subject to the complaint now made, that the jury were not properly instructed as to the burden of proving negligence.

Evidence of the condition of the bolt, immediately after thy accident was admissible.

Exceptions overruled.