Opinion by
Mr. Justice Mitchell,The first assignment of error we are obliged to sustain. The general effect of Lytle’s testimony was that Warfel said he had told the chief of police to notify Mrs. Long about her pavement in the fall of 1889, and yet it is conceded that Warfel was' not elected burgesfe of defendant until 1890. Lytle did not attempt to explain this discrepancy, and the learned judge should either have struck out the testimony as requested, or at least have called the jury’s attention to it, and instructed them distinctly that no notice or knowledge imputable to Warfel before he became burgess could in any way bind the borough. Instead of so doing however, he said, in refusing the motion to strike out, that such notice or knowledge in the fall of 1889 might “ bear upon the question whether or not as chief burgess he knew,” etc. This is contrary to the settled law. “ It is only during the agency that the agent represents and stands'in the shoes of the principal. Notice to him is then notice to his principal. Notice to him twenty-four hours before the relation commenced is no more notice than twenty-four hours after it ceased would be. Knowledge" can be no better than direct actual notice.” Sharswood, J., in Houseman v. Girard Ass’n, 81 Pa. 256. In referring to Lytle’s testimony, the learned judge in his charge did not instruct the jury on this point, and hence they maj'- well have supposed that if Warfel knew of the defect in 1889 his knowledge would continue and bind the borough after he became burgess.
But the most important error in the case is embodied in the fifth assignment. The learned judge calling the jury’s attention to the testimony that a pavement of hemlock boards such as this was, would not' last ordinarily over four to six years,. *249said that the chairman of the street committee and the chief of police (whose duty it was by ordinance to look after the sidewalks) were presumed to know this fact, and “ it was their duty to exercise proper supervision or make proper examination of this pavement by going upon and testing it to discover, if by the eye they could do so, whether the pavement was defective or not.” This was holding the borough to too stringent a rule of responsibility. It was in fact applying to it the measure of duty laid down for an employer in not only furnishing safe tools to his workmen, but in knowing their liability to decay, and in replacing them at the proper time : Baker v. R. R. Co., 95 Pa. 211. But there is a clear distinction to be taken between the duties in the two cases. That of the master is primary and absolute, to know and to do, while that of the borough, or of any municipality, as to sidewalks, is secondary and supplemental, to see that the property owner makes and maintains a safe pavement, and its breach of duty is not in failing to do the work, but in failing to compel the owner to do it. It is entitled therefore to notice, actual or implied, of the existence of the defect. This is the settled rule even as to defects in the street, where the duty to keep in repair is primary and mandatory. The charge of the learned judge would require the borough to know how long every pavement had been laid, and to keep informed of what repairs the owner had made upon it, in short, to seek for defects. The law only requires that it shall be vigilant to observe them when they become observable to an officer exercising reasonable supervision. The difference is not one of mere words, but one of great practical importance, for it is always .easy to show, after an accident, how the defect might have been found if it had been sought for; and to tell a jury that it is the duty of the municipality to seek, is to give them an opportunity, which few will hesitate to take, to make municipalities insurers against accidents of all kinds in the streets. In the recent case of Burns v. Bradford City, 187 Pa. 361, our brother McCollum: said: “ A municipal corporation is not an insurer against all defects in its highways, but it is answerable for negligence in the performance of its duties in the construction and care of them. For a defect arising in them without its fault or neglect, it is not liable, unless it has express notice, or the defect be so notorious as to be *250evident to all passers.” It was accordingly held in that case that although “ it is a fact well known to the inhabitants of all our municipalities that sidewalks are liable in the winter to be thrown out of level by the action of the frost,” yet the plaintiff, who was injured, very much in the same manner as the present plaintiff was, by the stringers of a plank walk being raised higher on one side than the other, could not recover without proof that the defect was observable by all passers. So here, the proper instruction to the jury should be that the borough was bound to keep a reasonable supervision over the condition of its sidewalks, but it was not liable for negligence unless it had actual notice or knowledge of the defect complained of, or it was so plain to observation and had existed so long a time that officers exercising a reasonable supervision ought to have observed it.
No case has been brought to our attention which holds any stricter rule than this. In Rapho Township v. Moore, 68 Pa. 404, it was held that when a bridge is old and has stood as long as the timbers usually last, it is negligence to omit proper precaution to ascertain its true condition. But there the duty to maintain the bridge was primarily and absolutely on the township, and the same element runs through all the other cases cited by appellee.
Judgment reversed, and venire de novo awarded.