Carpenter, J.
Real estate must be taxed in the town where it is situated. G. L., c. 53, s. 2; c. 54, s. 11. “The words ‘land,’ ‘lands,’ or ‘real estate’ shall include lands, tenements, and hereditaments, and all rights thereto and interests therein.” G. L., c. 1, s. 20. Easements are taxable: if appurtenant, they are in general taxed with and as a part of the land to which they belong. Easements in gross must necessarily be valued and taxed separately from the land out of which they are granted.
Water-power, or rights in a reservoir of water, are an interest in the land upon and by which they are created, and by the express terms of the statute must be taxed in the town where the land of which they are a part is situated. Although they may be so far severed from that land and annexed to land situated in another town as to pass without special mention in a conveyance of the latter, their geographical location is not thereby changed. The title to and occupancy of the land creating w'ater-power or reservoir rights may be in one person, and of the power and rights in another. In such case each must be separately assessed. The plaintiffs own both the reservoir rights, and the dam, gates, land, and flowage out of which they issue. Their water rights have not been severed from their lands in Gilford and annexed to their mills and other real estate situated elsewhere. By a conveyance of the former they would pass, and by a conveyance of the latter they would not pass, without special mention. If the reverse were true, they would be none tbe less real estate situated in Gilford. They were properly valued and taxed with the lands in Gilford. Cocheco Co. v. Strafford, 51 N. H. 455.
In the appraisal of a water-power, as of other property, all the facts and Circumstances affecting its value are competent evidence. The- assessors may consider the original cost of the entire property, the quantity of land flowed ■ and its value for other purposes, the magnitude of the power, its location and the place where it is or may be utilized, the uses to which it is or may be applied, together with the limitations, if any, either of the manner in which or of the purposes for which it may be employed, the income derived from it by way of rents or from its use by the owners, the expense of maintaining and managing it, the cost of equal power derived from other sources (that is, its comparative economy), the effect which the appropriation of the land for the purpose and the use of the power have to increase or to diminish the value of the owner’s other lands, and their like effect upon the property of others, — in short, anything which might justly affect the judgment of a person desiring to purchase in determining what price he would offer. Cocheco Co. v. Strafford, 51 N. H. 455, 476-478; Low v. Railroad, 63 N. H. 558, 562. If a soap factory tends to depreciate