A city ordinance, prohibiting the driving of any vehicle in the streets of the city at a greater rate of speed than six miles an hour, is binding upon all persons driving within the city, as any statute or other law of the Commonwealth ; and to drive faster than the prescribed rate is a violation of law. Heland v. Lowell, 3 Allen, 407. It appearing in this case that the city of Lawrence had passed such an ordinance, it was incumbent on the plaintiff to show that she was not violating it. If at the time of the accident she was doing an unlawful act, and that unlawful act contributed to cause the alleged injury, she was not in the exercise of that due care which she is obliged to prove in order to recover. The allegation of due care implies not only that the plaintiff was not negligent, but also that she was not acting in vio- , lotion of law when the alleged injury-occurred. The fact of due care on the part of the plaintiff was directly in issue; it was alleged in the declaration and denied in the answer. On that issue the plaintiff had the burden of proof, and if she failed to sustain the burden, she must fail in her action. Bosworth v. Swansey, 10 Met. 363. Jones v. Andover, 10 Allen, 18. Wright v. Malden & Melrose Railroad, 4 Allen, 283, 290. Worcester v. Essex Merrimac Bridge, 7 Gray, 457. We are therefore of opinion that the learned judge erred in ruling that the burden of proof was on the defendant to show that the plaintiff was violating the city ordinance by driving more than six miles an hour when she met with the injury complained of.
We see no ground of exception to the rulings on the admissions of evidence. It was clearly within the discretion of the presiding judge to limit the inquiry as to the speed that the horse was capable of going. Stone v. Hubbardston, 100 Mass. 49. It was offered to contradict statements elicited on cross-examination, and *279does not appear to have had any necessary bearing upon the rate of speed the horse was travelling at the time of the accident.
Nor was it proper to ask a witness, who saw the accident, if it was possible for the sleigh, at the angle at which it was crossing the horse railroad track, to have gone into the excavation. The witness was not asked to state what he saw, but to give his opinion as to what would happen or be likely to happen under given circumstances.
As the ruling on the burden of proof was erroneous, the entry must be Exceptions sustained.