In the opinion which was given in this case when it was first before us are these words: “ The fact that a road is so constructed that it is not likely to keep in good condition for a great length of time, will not impose liability on the town which is bound to keep it in repair, unless the danger is so imminent that it can fairly be said to show a want of reason*573able care and diligence to omit guarding against it at once.” Stoddard v. Winchester, 154 Mass. 149.
There was abundant evidence to warrant the jury in finding the road defective within the principle thus stated. The accident occurred on November 27, 1888, on a steep incline, where a trench had been dug during the last week in May of the same year. There was evidence that this trench was four and a half to five feet deep, and that a great deal of water came into it from the sides or bottom, so that to lay the pipe the workmen were obliged to dam up the trench to hold the water in different sections while laying pipe below, and when the pipe was laid in the section below, they were accustomed to take away the dam and ‘let down the water, and afterwards fill up the trench by throwing earth into the water, and in some portions treading it down. There was evidence that they could not tread down some portions of it owing to the water and the soft condition of the filling. There was also evidence that there was a soft spot when they dug the trench near the place of the accident, and that the loam and soft material that came out of that spot were thrown back upon the water in the trench, and that the men did not tread that down through fear of going in themselves. The superintendent of the waterworks, who had charge of laying the pipe and who visited the place once or twice a day, denied that there was such a soft spot as testified to by other witnesses, but said, if there was such a spot, filling in with loam would not make a safe job, and that a proper way to do the work would be to remove the loam and put in gravel.
The weather was dark and stormy at the time of the accident, and there had been a steady fall of rain for the two days immediately before. The horse suddenly sank into the road-bed, going in up to his crupper, with his nigh forward foot resting on solid ground on the opposite side of the ditch. The nigh side of the wagon also sank into the ditch, and the earth in the trench was soft to the depth of about four feet. The evidence in regard to the manner of doing the work was not before the court at the former trial. The doctrines laid down in Monies v. Lynn, 121 Mass. 442, and 124 Mass. 165, have been modified by the passage of the St. of 1877, c. 234. Pub. Sts. c. 52, § 18. Olson v. Worcester, 142 Mass. 536.
*574From this evidence the jury might well have found that the workmen were negligent in digging and filling the ditch, and that the road was defective for six months previously to the accident, and that the exercise of reasonable diligence would have prevented the existence of the particular defect which caused the accident. Any one who knew the condition of the earth there, and how the ditch was filled, might well expect that the place of the excavation would become soft and dangerous any day on the fall of a heavy rain. There was evidence that the way was defective, and that the plaintiff was in the exercise of due care.
Was there evidence that the town had notice of the defect, or might have had notice thereof, by the exercise of proper care and diligence ? If the work of digging and filling the trench had been done by the authorities in charge of the repairs of the streets, the question would be too simple for argument. It was ■ done by the superintendent of the waterworks, whose general duty was to attend to another department of the public business. Was he an agent or servant of the town in reference to his work done in the public streets, so far as to make the town chargeable with his negligence in doing that which would naturally affect the condition of the streets? We are of opinion that he was. He was certainly an agent of the town in his own department. He was permitted by the town to represent it in digging up streets to lay water-pipes. His work necessarily created dangers in the streets, and called for careful attention in restoring the streets to a safe condition. If that work was intrusted to him either by the town in its corporate capacity, or by the public officers who were charged with the duty of keeping the streets safe in behalf of the town, the town ought to be chargeable with his negligence to the same extent as if the work had been done by a highway surveyor. If the negligence was that of the servants of the superintendent of the waterworks, the same rule should apply as if the work had been done by the servants of the highway surveyor. They are all engaged in the service of a common employer in doing work affecting the safety of the public streets. There is no good reason for making a distinction between them in regard to charging the town with notice of their acts. In Hand v. Brookline, 126 Mass. 324, and *575Monies v. Lynn, 121 Mass. 442, the court seems to make no distinction between defects caused by those charged with the re- - pairs of the streets and those caused by persons engaged in some other department of the city or town.' We are of opinion that there was evidence on which it might have been found that the town either had notice of the defect, or by the exercise of reasonable diligence might have had notice of it.
The question to the witness Dotten in regard to the work on the dam was rightly excluded. That work had no connection with the work in the trench, and there was no occasion to inquire about it.
The questions to the expert witness Perkins were also rightly ruled to be improper. He had no personal knowledge of the trench, and the questions called for an expression of opinion founded on his understanding of the testimony, and his inferences ■ of fact from it. If he had answered the questions, the jury would not have known the effect to be given to his answers, because they would not have known what view he took of the facts, nor on what he was giving his opinion. The proper way to interrogate an expert, to obtain his opinion on facts to be derived from testimony, is to put questions on hypothetical statements of facts, or to ask the witness to give opinions founded on possible views of the evidence, stating in connection with the opinions the hypothetical facts to which they relate, so as to make them intelligible. An expert witness cannot be asked to give an opinion founded on his understanding of the evidence, against the objection of the other party, except in cases where the evidence is capable of but one interpretation. In other words, questions must be so framed that the witness will not be called upon to give an answer involving his opinion on disputed questions of fact which are not proper subjects for the testimony of an expert, nor to intimate to the jury his opinion as to the credibility of any of the witnesses. Woodbury v. Obear, 7 Gray, 467. Hunt v. Lowell Gras Light Co. 8 Allen, 169.
Exceptions sustained.