Opinion by

This is ail action of trespass brought to recover damages for a personal injury suffered by the plaintiff, which he alleges resulted from the negligence of the defendants. His right to recover depends upon his ability to show the negligence of which he complains, and that it was the proximate cause of his injury. The circumstances surrounding the accident, as disclosed by the testimony, were substantially these. The plaintiff had been during the early evening of the 81st of August, 1890, at the house of an acquaintance near the corner of Sixth street and Montgomery avenue in the city of Philadelphia. He started to return home at about 9:30 o’clock. His route was down Sixth street in a southerly direction, one square to Columbia avenue, west on Columbia avenue one square to Seventh street and southerly again, down Seventh street to some point below Oxford street. He turned down Seventh street on the east side, and for about one hundred feet the houses were all occupied and the footwalks in front of them were in good condition. At the end of this distance a narrow alley crossed the walk, and from this alley down to Oxford street a row of twenty-two new houses was in process of construction. The sidewalk in front, of this row was in an unfinished condition. It had been graded ready for the surface of brick or asphaltum, but no part of it was completed, and at least one half of its breadth was incumbered with building materials. Near the middle of the outer half of the graded footwalk, or two or three feet from the curb, in front of the second house from the alley, a block of stone was lying. Beck, on reaching the alley, crossed it and entered upon the unfinished walk in front of the row of new houses, walking rapidly. He ran against the block of stone and injured one of his legs quite seriously, and for this injury he now seeks to recover in this case. Hood was owner of these new houses, and was building them by contracting with mechanics and material men for different portions of the work. Keegan was one of these contractors, and his undertaking was to furnish the stones used about the steps and foundations, and put them in place. The block against which Beck ran was intended for use in the front steps of the second house from the alley, in front of which it lay, and had been delivered by Keegan’s employees before the close of the day of the 31st of August. The contention of *37the plaintiff was that it was the duty of Hood, as owner and builder, to protect the public from the danger of injury on account of the unfinished and incumbered condition of the sidewalk, by barricading or fencing it off at both ends, and by the display of lights, so as fully to warn the public of the situation. He also contended that it was the duty of Keegan when the block of stone was delivered to him upon the unfinished walk, to remove it to some less exposed position or, if for any reason this was not practicable, to protect passers, by the use of lights or by the erection of barriers about it. The defendants set up the exercise of due care on their part by the display of red lanterns near the curb and just below the alley, and the erection of barriers at each end of the building operation.

They also alleged that the street was well lighted, that the fact that a building operation was in progress was perfectly obvious to every traveler on the street, and that the stone with which Beck collided was plainly visible and should have been avoided by one exercising common care. On the trial the plaintiff took the witness stand in his own behalf and testified at length in regard to all the contested questions of fact involved. He denied the existence of barriers across the walk, of red lights at the proper places, and of the sufficiency of the street lights to enable him to see that a building operation was in progress or that the walk was incumbered with materials. He alleged on the other hand that the walk was hard and smooth, and that there was nothing in its condition to warn him that it was unfinished, or to put him upon notice.

While his cross-examination was in progress counsel for defendants proposed to show by him, “ for the purpose of attacking his credibility, and with a full understanding that I am bound by his answer, that on a previous trial of this cause, and during its progress he, the plaintiff, met the foreman of the jury, which was then trying the case, out of court, took him to a tavern on Sixth street, bought him liquor and then induced him to go to his, plaintiff’s, house and place of business at No. 813 Marshall street, and there talked to said juror in regard to the probability of the verdict to be rendered by the said juror and his fellows, and attempted to demonstrate to said juror his, plaintiff’s, physical inability to perform his work as a printer.” This offer was objected to as inadmissible for the purpose proposed; *38tbe objection was sustained and tbe offer excluded by tbe court. This ruling is the subject of the first assignment of error. The rule limiting the right to cross-examine with a view to affect the credibility of the witness is stated in the case of Elliott v. Boyles, 31 Pa. 65. If the examination is directed to collateral matters the court may limit, and under some circumstances exclude it; but if directed to the situation of the witness, his relations with the party calling him, his zeal or bias as shown by his conduct, or by improper efforts to influence witnesses or jurors in the case trying, it is, within proper limits, a matter of right: Cameron v. Montgomery, 13 S. & R. 128. When the party becomes a witness for himself he stands in no better position than any other witness not a party. His credibility may be attacked by the same methods, and his conduct when he attempts to corrupt the administration of justice is subject to investigation in the same manner. The facts set out in the rejected offer were such as if proved before the jury would have been an impeachment of the character of the plaintiff, and a moral conviction of a misdemeanor. They were not only sufficient to affect his credibility, but their force could not have been readily avoided.

It is not necessary to go at length into a discussion of the modern doctrine in regard to cross-examination, or the introduction of evidence for the purpose of discrediting a witness, for the cross-examination proposed is not on debatable ground. It was clearly admissible. Counsel for appellee seems to rely upon Buck v. The Commonwealth, 107 Pa. 486, as holding an opposite doctrine, but it is really in harmony with the rule we have stated. In that case it was sought to show that the witness had been indicted and convicted of an offense at some previous time, in order to affect his credibility, and it was said that the record of the conviction was the proper evidence of the fact. There was no such question here. The offer was to show that the witness, who was also the party, had on a former trial of this case sought to reach the jury that had been sworn for its trial by ex parte statements and by other methods equally reprehensible, which were intended to affect their verdict. There was no record by which the facts stated in the offer could be shown. If they were admissible, about which we have no doubt, the offer to show them by a cross-examination of the *39witness against whom they were alleged was a proper method of proof. The first assignment is sustained. The fourth assignment of error is to an instruction in the general charge in relation to the liability of Keegan. The learned judge said to the jury: “ As to Mr. Keegan, he put the stone there and had control of it while it was there; and if there be any liability for negligence it is obvious that in the act of negligence he was a participant.” This was in effect a binding direction that if Hood was guilty of negligence then Keegan was as a “participant” in the act of negligence also guilty. This does not necessarily follow. The negligence, if any was found to exist, may have been chargeable to Hood, or to Keegan, or both might have been found equally careless of the safety of the public. The question was one of fact for the determination of the jury, not of law for the decision of the court. The negligence of Keegan, like that of Hood, depended upon his own acts or omissions, and not on those of another. Each had a duty to perform and each must stand or fall upon the manner of his performance. If Keegan put or caused the stone to be put upon the sidewalk he had no right to rely upon a temporary barrier erected by Hood, without giving attention to its maintenance or otherwise warning or protecting the public. It may be that under all the circumstances of this case the direction now considered did the defendant no harm, but as the case must be reversed upon the first assignment, the true rule on this subject should be pointed out.

The sixth assignment is directed at the answer by the learned judge to the defendants’ fifth point. The instruction asked was that the true ground of liability in actions for negligence was “ not danger but negligence, and the test of negligence is the ordinary usage of business.” This is undoubtedly the general rule, Ford v. Anderson, 139 Pa. 263, and should have been affirmed by the court, and the possible exceptions pointed out. The answer was “ I refuse that point in the form in which it is stated; the test of danger is the ordinary usage of business if the ordinary usage of the business was the exercise of ordinary care under the circumstances.” This was really an affirmance by the learned judge of the rule stated in the point in the very words of the point, with a qualification denying its effect in cases where an ordinary usage of business was below what ordi*40nary care would require. This was right in effect, although the formal refusal of the point might possibly mislead the jury to some extent as to the general effect of the answer. One other subject brought to our attention by the fifth assignment of error requires notice. The defendants’ third point asked the court to instruct the jury that if the sidewalk had been poled or fenced off by the defendants on that evening before the happening of the accident, and the pole had heen taken down without the defendants’ knowledge, by parties over whom they had no control, they were not liable for the accident. This instruction was properly refused. . It would not be enough for a builder to fence off a part of the walk, because it was in a dangerous condition, and then give it no more attention. He knows the probabilities of the removal of the barrier by mischievous or disorderly persons, and he should exercise reasonable care to see that it is in place. It might not be necessary to maintain a watchman at the spot during the night, but the builder should give some attention to this subject during the evening, and while the walks are actively occupied, in order to be sure that the lights and barriers he has provided to protect the public are in place and are doing their work. How well this had been done in this case was for the jury. The pole was certainly down, according to the plaintiff’s testimony, when he came upon this part of the walk, although it had been found in place but a few moments before. There was an electric street light at Columbia avenue a little more than oné hundred feet away. There was another at Oxford street or near the other end of the row of houses, and there was a gas burner about midway between them upon the other side of the street. There were red lights also displayed within a few feet of the block of stone at the curb. Whether there was light sufficient to enable one exercising ordinary care to see where he was going, or warnings sufficient in the red lights at the curb to attract his attention, are questions that, upon a new trial, should be distinctly brought to the attention of the jury.

For the reasons given in this opinion the judgment is reversed, and a writ of venire facias de novo awarded.