The plaintiff, on the facts stated in the report of the referees, is not entitled to the sum assessed for damages caused by the erection of a bridge by the Boston and Maine Railroad over the Spicket River. The burden of proof was on the plaintiff to show a breach of the covenant against incumbrances. To show such breach by the erection of the bridge, which caused water to flow back on his land, it was necessary for him to establish a legal right in the Boston and Maine Railroad to obstruct the stream. The defendant did not covenant against the unlawful and tortious acts or trespasses of third persons, but only against such rights or easements in the premises conveyed as constituted legal incumbrances thereon. It does not appear by the report of the referees, that any evidence was offered by the plaintiff as to the mode in which the bridge was built, or whether it was lawfully erected over the river by the railroad corporation. If it was built in a reasonable and proper manner, within the due exercise of the power conferred on the corporation by their franchise, and for the purpose of constructing their road in a convenient and suitable manner, then it was a lawful erection, and the right to flow back water on the land conveyed to the plaintiff by the defendant would be a lawful incumbrance, for which an action of covenant would lie. But if the bridge was built in a mode not required for the due, *54reasonable and proper construction of the road, or the obstrue tian of the stream was a wanton and careless act on the part of the railroad corporation, not necessary to the due exercise of its franchise, then there was no breach of covenant. In such case, the acts of the railroad were tortious and unlawful, and the plaintiff’s remedy therefor was by an action of tort against the railroad corporation. Mellen v. Western Railroad, 4 Gray, 301. Perry v. Worcester, 6 Gray, 544.
This case was decided, and the subsequent cases were argued, at Boston in January 1858; present all the judges but Thomas, J.