The question put on cross-examination obviously was put for the purpose of discrediting the witness’s testimony by his admission that he had not been asked, and by implication that he had not spoken, about the condition of the sidewalk, or had his attention directed to it until a date long after the time in question. It was competent on re-examination to show that he was mistaken in his answer, and had spoken about it at a much earlier time. Commonwealth v. Wilson, 1 Gray, 337, 340.

Exceptions overruled.