Towns are required by statute to keep all highways and town ways within their respective limits in repair, “ so that the same may be safe and convenient for travellers.” Rev. Sts. c. 25, § 1. It was not sufficient therefore for the de*230fendants to show in the present case that the way was safe, so that a person might travel over it without danger to life or limb. A further duty was imposed upon them. The road was to be kept in such condition that it might be used with ease and convenience. Proof that it was inconvenient, so as to be burdensome to the traveller, supported the indictment, because it showed that the defendants had been guilty of a breach of a legal duty imposed by statute. Commonwealth v. Springfield, 7 Mass. 9. Mower v. Leicester, 9 Mass. 247. In considering the degree of negligence which would render the defendants liable, it was proper for the jury to take into view the state of other roads, similar in their construction, situation and use to that which was the subject of indictment. Negligence is a relative term. The jury must have some means by which to judge whether the defendants had violated their duty; and it certainly was not establishing too high a standard, or holding them to a too strict rule, to require that they should use the same diligence as was exercised by others charged with like duties and obligations as were imposed upon them. So far we are of opinion that the instructions were correct.
But they seem to us to be erroneous and deficient in that portion of the charge which related to the legal liability of the town to support and repair the road set out in the indictment. There having been no proof that the way had ever been laid out in the manner prescribed by statute, it could have become a public way chargeable on the town only by prescription or dedication. To establish a way by prescription it was necessary to prove an actual public use, general, uninterrupted and continued for at least twenty years. Jennings v. Tisbury, 5 Gray, 73. To render it a public way by dedication only, it was essential to show some act or prove some circumstances from which an assent to and acquiescence in such dedication by the town might be properly inferred. Bowers v. Suffolk Manuf. Co. 4 Cush. 332. But in either case it was necessary to show that it had become a public way prior to St. 1846, c. 203, which provides that “no way heretofore opened and dedicated to the public use and not already become a public way, *231and no way hereafter opened and dedicated to the public use, shall become chargeable upon any city or town, unless such way shall be laid out and established by such city or town in the manner prescribed by the statutes of this commonwealth.” This provision seems to have been overlooked at the trial of this case. Under it the road in question could not have become chargeable on the defendants, unless it had become a public way either by prescription or dedication prior to its enactment. The attention of the jury was not called to a consideration of the facts in evidence in the light of this provision, and it is impossible to support their verdict, because it cannot now be known that it may not have been founded, either in whole or in part, on the proof of the use of the road as a public way since the statute above cited was passed. Exceptions sustained.