Opinion by
W. D. Porter, J.,The property of the plaintiffs was situated in the township of East Pike Run and abutted upon a public road, which led through the borough of California and continued out through the township. In front of the property of the plaintiffs half of the highway, longitudinally, was within the borough and the other half in the township, the boundary being the center line of the road. This proceeding was instituted to recover for injuries resulting to the property of the plaintiffs from a change in the grade of the road by the officers of the borough. No objection to the form of the action was made in the court below, nor has that question been argued here, and for that reason we do not deem it incumbent upon us to consider it. The learned counsel who represented the appellant has confined his argument to the merits of the case, the right of the plaintiffs to recover, under the evidence, in any form of action. The grounds upon which he seeks to reverse the judgment are: (1) That there was no evidence to warrant a finding that the work was done under the authority of the borough; (2) that even if the borough authorities procured the work to be done it was not within the scope of their duties and the borough was not liable for the consequances; and (3) that the court charged as matter of law that the plaintiffs were entitled to recover interest from the time the work was done.
A number of witnesses testified as to the manner in which the grading was done and the disposition which was made of the material taken from the bed of the road by using it in grading *239other streets within the borough. It was admitted that the work was done by and under the direction of the street commissioner of the borough, and there was direct evidence, which was not contradicted, that the work was paid for by the proper borough authorities. There was evidence as to the declarations of the borough street commissioner, while acting within the scope of his authority in doing the work, as to the character in which and the orders under which he was acting. These declarations were evidence as part of the res gestae. The acts of a municipal corporation may'be proved otherwise than by its records or other written document, and the testimony of the witnesses called by both parties in the court below was such as to warrant a finding that the work was done by authority of the' borough: Weir v. Plymouth Borough, 148 Pa. 566; Bohan v. Avoca Borough, 154 Pa. 404.
The borough could not have vacated or changed the location of the road in question: Somerset and Stoystown Road, 74 Pa. 61; South Chester Road, 80 Pa. 370. The road had long been used as a public highway and there is no question that it had been located and opened under legal authority. The Act of April 1, 1834, P. L. 166, imposes upon the authorities of a borough the duty to open such parts of any road laid out by order of the proper court as are within the borough limits. All public roads or highways are required by law to be constantly kept in repair, which duty is to be discharged by each municipality as to the highways within its limits. The authorities upon whom is imposed the duty to open a road laid out by order of the court are vested with a reasonable discretion to determine the amount of grading necessary to accomplish the result. The order of the court fixes the location of the road; the authorities of the boroughs and townships within which it is located cannot change the location, but they exercise a discretion as to the amount of cutting and filling which upon that location is necessary to make the road reasonably safe and convenient for travel. The Act of April 3, 1851, P. L. 320, section 2, expressly delegates to boroughs the power to régulate the roads, streets, lanes, etc., and the heights, grades, widths, slopes and forms thereof, “ and they shall have all needful jurisdiction over the same.” The authority to grade all streets and roads within the corporate limits is among the im*240plied, powers of a municipality : City of Williamsport v. Commonwealth, 84 Pa. 493. A borough may lawfully grade that part of an old township road which is within its boundaries: White v. Borough of McKeesport, 101 Pa. 394. When no specified grade has been fixed by the borough, but changes in the actual grade of a street are made from time to time in repairing the highway, the borough is answerable for the injury to property resulting from such changes: New Brighton v. Peirsol, 107 Pa. 280. In repairing a public road municipal authorities are vested with a discretion to make such changes in the grade as have been rendered necessary by the wear of travel and the action of the elements, or as have become expedient because of an increase of the traffic or a change of its character. One half of the public road directly in front of plaintiffs’ property was in the borough of California; with regard to that half the borough had jurisdiction and was charged with a duty. The borough could not make such changes in the grade of that half of the road as to interfere with the use of the public highway in its entirety; that half must be maintained at a grade which would permit of its being used in connection with the other half. The borough authorities might, with the acquiescence of the authorities of the township, make such change in the grade of the whole width of the road at that particular point as was necessary to keep the highway in repair. While the duty of the borough and township was not a joint one, they were each charged with a duty, the discharge of which contributed to a common result. The authorities of the borough were vested with a discretion to determine the manner in which their half of the road could most economically be kept in repair. If in their judgment that end could best be accomplished by carrying their work beyond the riiiddle of the road they might, with the consent of the authorities of the township, in that manner discharge the duty of the borough to maintain the highway. The borough must answer for the injuries resulting to private property from the manner in which the duty imposed upon it by law was discharged.
The learned judge helow inadvertently directed the jury to allow interest, from September, 1898, to the time of the trial, March, 1901, as matter of law. This was a technical error: Provident Life & Trust Company v. Philadelphia, 202 Pa. 78. *241The amount by which this error increased the verdict, however, was not large and is easily ascertainable. We will follow the precedent established by the Supreme Court in Richards v. Citizens Natural Gas Company, 130 Pa. 37, and permit the appellee to yield the amount by which the verdict was so increased, by striking off the amount of the interest during the period stated. We will not now make a final order, but if the plaintiffs shall within twenty days file a stipulation reducing the judgment nunc pro tunc, as of March 16, 1901, to $1,000, the judgment will be affirmed.