The plaintiff's purpose in removing the stud was to weaken the structure. He intended his act should contribute, at least, to cause the timbers to fall. It was the result of *Page 565 the exercise of his own judgment with a full knowledge of the facts. He must have known that it was liable to fully accomplish the object in view. The risk of injury from falling timbers was incident to his service, and must have been known to him if he exercised due care. It was assumed by him in entering upon the service. Fifield v. Railroad, 42 N.H. 225; Nash v. Company, 62 N.H. 406; Henderson v. Williams, 66 N.H. 405.

The testimony excluded related to a matter of common knowledge as to which the jury could judge as well as any one upon being informed of the situation.

Exceptions overruled.

WALLACE, J., did not sit: the others concurred.