This is a petition for the assessment of damages occasioned by taking an easement for laying a water main by the respondent under the power of eminent domain conferred by St. 1884, c. 256. The petitioners were the owners of the fee of the land within which the easement was taken. It had been “dedicated by the owners of the fee as” a private way called Clark Street in the city of Waltham, but it was unbuilt and was passable for teams only for a portion of its length. It was part of a large tract of land which had been plotted into streets and building lots, some of which had been sold and built upon before the events here in question. It is stated in the bill of exceptions that “the respondent as trespasser” had entered upon Clark Street and constructed a concrete conduit for a water' main about a year before the taking, which by description included the land wherein the main had been constructed. It is stated in the respondent’s brief that for this trespass an action was brought by the present petitioners and damages recovered, but this must be disregarded for there is no reference to it in the exceptions. The respondent, as a municipality in general pursuing authority conferred by the State in supplying water, may be liable for a trespass committed by its servants outside its statutory power. Mayo v. Springfield, 136 Mass. 10. Aldworth v. Lynn, 153 Mass. 53.
The first question is whether the conduit, having been built within the land subsequently taken by the respondent, then became a part of the real estate and the property of the petitioners, so that they are entitled to have their damages assessed on that basis. It is familiar law that, ordinarily, when buildings or other structures are annexed to the realty in such way as to become incorporated with it by a trespasser, or without express or implied agreement to the contrary, they are a part of the land and belong to the owner who “has the right to that which is united to it by accession or adjunction.” Peirce v. Goddard, 22 Pick. 559. There are many illustrations of the application of this principle in our cases. It was held in Meriam v. Brown, 128 Mass. 391, that where a railroad company had constructed its track over land without right, and without paying damages, and without *511making a taking, and subsequently became bankrupt and abandoned the use of its roadbed, the rails had become a part of the land and could not be removed. It was said in Hunt v. Bay State Iron Co. 97 Mass. 279, that railroad rails upon private land became part of the realty in the absence of agreement to the contrary and enured to the benefit of the landowner. Buildings and other structures annexed to land by one rightfully in possession but without the consent of the owner, generally have been held to be a part of the realty. Meagher v. Hayes, 152 Mass. 228. Difficulties of this nature often arise between landlord and tenant and mortgagor and mortgagee. But the law is settled even under these circumstances that the owner of the land is the owner of the things incorporated with the realty unless there is some special agreement. Trask v. Little, 182 Mass. 8. Mitchell v. Stetson, 7 Cush. 435, 439. Clary v. Owen, 15 Gray, 522. South-bridge Savings Bank v. Exeter Machine Works, 127 Mass. 542. Hook v. Bolton, 199 Mass. 244. Gloucester Water Supply Co. v. Gloucester, 179 Mass. 365, 377, 378. Porter v. Pittsburg Bessemer Steel Co. Ltd. 122 U. S. 267.
We are able to perceive no sound reason why this well established rule should not apply in instances where a municipality enters without shadow of right and as a pure trespasser upon the land of another and without consent of the .owner affixes thereto structures which in their nature become part of the realty. A municipality enjoys no special immunity in this respect not accorded in general to others. It commonly possesses the power to exercise eminent domain and thus take the property of the landowner against his will. This factor affords it the less excuse for invading tortiously rights which it may extinguish in a legal manner.
This conclusion is supported by the decisions of courts of recognized authority. St. Johnsville v. Smith, 184 N. Y. 341. Virginia & Southwestern Railway v. Nickels, 82 S. E. Rep. (Va.) 693. Similar decisions in United States v. Land in Monterey County, 47 Cal. 515, and Graham v. Connersville & New Castle Junction Railroad, 36 Ind. 463, perhaps have been distinguished or overruled by the later cases of Albion River Railroad v. Hesser, 84 Cal. 435, 439, and McClarren v. Jefferson School Township, 169 Ind. 140, 144.
*512If the circumstances were that the city had been lawfully in possession of the land under a defective title and in good faith or by agreement or consent had attached permanent improvements to the soil, a different question would arise which need not be decided now. See Searl v. School District No. 2 in Lake County, 133 U. S. 553, 561; Consolidated Turnpike Co. v. Norfolk & Ocean View Railway, 228 U. S. 596, 602; and R. L. c. 179, §§ 17, 18.
Numerous authorities more or less inconsistent with the conclusion here reached are collected in 2 Lewis, Em. Dom. (3d ed.) § 759, and 6 Ann. Cas. 382, 384. But so far as they are out of harmony with the principles here stated we cannot see our way to follow them.
The sixth ruling requested by the petitioners should have been granted, and so much of the charge as was contrary to this principle was erroneous.
At the new trial the petitioners will be entitled to recover for the diminution in the fair market value of their land arising from the taking of the easement. In passing upon this question the jury may consider the fact that the conduit was constructed in the portion of the way in which the easement was taken. Of course the petitioners will not be entitled to recover the cost of the conduit nor the value of it to the respondent. The existence of the conduit upon the land may be treated as an element affecting the fair market value so far as it would enter into the price which would be given for the petitioners5 rights in the land by a prospective purchaser. If it be found to be a certainty that the respondent would be bound to make the taking of this particular property, that circumstance is not an element of value. If the petitioners proceed to trial upon the theory that the diminution of the fair market value will not compensate them for the damage sustained by the taking and seek to have considered the real value for actual use upon the principles stated in Beale v. Boston, 166 Mass. 53, in this respect the rule is the same: they are not entitled to have their damages enhanced by the certainty, if it be found to be a reasonable certainty, that the city would make a taking of the property in question. May v. Boston, 158 Mass. 21. The familiar general rule of damages has been stated so fully in many cases that it need not be repeated. Sargent v. Merrimac, 196 Mass. 171. *513Smith v. Commonwealth, 210 Mass. 259, and cases there cited. McGovern v. New York, 229 U. S. 363, 372. United States v. Chandler-Dunbar Water Power Co. 229 U. S. 53,77. Pastoral Finance Association, Ltd. v. The Minister, [1914] A. C. 1083,1088. Cedar Rapids Manuf. & Power Co. v. Lacoste, [1914] A. C. 569, 579. It may be added that if the evidence at the new trial should not differ materially from that disclosed upon the present record, the diminution in the fair market value will be the rule of damage to be followed.
The petitioners’ eighth request was denied rightly as inapplicable to the issues being tried. The trial did not proceed on any theory that the respondent had laid its conduit in such a “way” as is described in St. 1884, c. 256, § 3, and hence was not liable to pay damages therefor. Cheney v. Barker, 198 Mass. 356, 362. New York, New Haven, & Hartford Railroad v. Cohasset Water Co. 216 Mass. 291. When the petitioners’ right to maintain their petition depended on a taking made by the respondent on the basis that it was a private and not a public way, it would have tended only to confuse the jury to undertake to deál with law which would not aid in deciding the case. Submitting the case to the jury was a granting of all that was pertinent in that request.
The judge ruled correctly that the taking by the respondent for the purposes here disclosed did not give to the respondent the right to prevent the construction of a sewer over its conduit by any one having a right to build a sewer in the way. The respondent had constructed a cement conduit of most durable material and designed to last a long time. It was buried during its course through Clark Street on an average twenty-three feet below the surface, although for a short distance it was only two feet below the surface. The only easement acquired by the respondent was to use the land in connection with its water supply. It did not acquire the fee of the land. The structure being so constructed, it is plain that it could not prevent the owner of the fee or others empowered so to do from making reasonable structures above its conduit. Clark v. Worcester, 125 Mass. 226. Newton v. Newton, 188 Mass. 226. Allen v. Boston, 159 Mass. 324.
The third request of the respondent, in substance to the effect that the jury would be warranted in returning a verdict for the *514respondent provided they found that the natural and probable uses to be made of the easement taken by the respondent would not prevent its use as a private way by the owners of the fee, was qualified by the instruction that they should consider also any interference with that use which might arise from the fact that the respondent had acquired the right to interfere with such use to some extent. It should be qualified further by the statement that the conduit laid by the city before the taking should be considered, provided it added anything to the market value of the fee of the land owned by the petitioners.
The instruction to the effect that the city of Waltham might lay out a street over the private way notwithstanding the taking of the respondent is not open to objection.
Exceptions sustained.