delivered the opinion of the Court. Several very important questions have been submitted to the Court in the present case, some of which, for reasons which will sufficiently appear, it is not now necessary to decide. An abstract of *390the bill and a general view of the case, and of the questions arising under it, will appear by reference to the report of a former decision, in the same case, upon the preliminary question °f jurisdiction. 16 Pick. 512. The case then came before the Court on a general demurrer, in which all the facts alleged by the plaintiffs were admitted ; and the question was, whether if the plaintiffs held and enjoyed all the rights set forth in their bill, and if without legal authority they had been infringed by the defendants, in the manner therein set forth, the plaintiffs were entitled to relief in a court of equity ; and the Court held that they were. The question now arising is a very different one, and depends mainly upon the construction and legal effect of the several legislative acts under which the parties respectively claim. For the purposes of this hearing it is admitted, by the defendants, that the piers, embankments and bridges erected by them in the construction of the Boston and Worcester rail road in and over the full and receiving basins claimed by the plaintiffs, do, to a certain extent, diminish the volume of water which those basins would otherwise contain, and do therefore to some extent impair and diminish the water power to be derived therefrom. But they insist that this is damnum absque injuria, that they are legally justified in so laying out the rail road over the basins, that the damage thereby suffered by the plaintiffs is not in consequence of a tort done by the defendants, to be deemed in law or equity a nuisance, or abated as such, but an act done by rightful authority, for which the remedy is by a compensation in damages, to be obtained in the manner provided by law. This, at present, constitutes the question between the parties. This is a question involving public and private interests of very great magnitude, and requiring the most mature consideration. In deciding it, the Court have the satisfaction of feeling that they have derived great benefit from a full, able and ingenious argument, which seems quite to have exhausted the subject.

The first question which we propose to consider is, whether the legislature had the legal and constitutional authority to grant to the corporation created for the purpose of establishing a rail road from Boston to Worcester, the power to lay their road over and across the basins of the plaintiffs, on paying them the *391damage sustained thereby, and to keep up and maintain the same.

It is contended on the part of the plaintiffs, and this constitutes one of the main grounds of their complaint, that the legislature had no such authority, because they hold a franchise in and over all the lands, flats and waters included in their full and receiving basins, obtained by a grant from the Commonwealth for a valuable consideration, and that the authority contended foi by £ie defendants would constitute an interference with and an encroachment upon their franchise, amounting in substance and effect, to revocation or destruction of the franchise, and a withdrawal of the beneficial uses of the grant. In order to judge of this, it is necessary to consider the nature and origin of the plaintiffs’ rights as claimed and set forth by them, and the manner in which they are affected by the acts of the defendants, supposing them warranted by the act of the legislature.

We do not now stop to inquire into the objections taken by the defendants, that the plaintiffs have not complied with the conditions of the grants made to them, by the act incorporating the Boston and Roxbury Mill Corporation, and the several subsequent acts ; that is a subject of separate and distinct consideration. Supposing them to have complied with those conditions, what are the rights claimed by them ? The plaintiffs were authorized to inclose and pen up a portion of the navigable waters adjoining Boston, so as to prevent the ebb and flow of the tide therein, and to discontinue any further use thereof by the public for purposes of navigation, to make use of part of the public domain, being all that part of the land covered by water lying below low-water mark, or more than 100 rods from high-water mark, and to acquire by purchase or by appraisement, without the consent of the owners, that part of the soil belonging to individuals, and to have the perpetual use thereoi for mill purposes, and to make a highway on their dams and take toll thereon. Other rights, no doubt, were incident, but this is a summary of their important rights and privileges.

The effect of the authority granted to the rail road corporation to lay their road over these basins, was to some extent to diminish their surface, and reduce their value. But the *392Court are of opinion, that this could in no proper legal sense be considered as annulling or destroying their franchise. They could both stand together. The substance of the plaintiffs’ franchise was to be a corporation, to establish a highway and take toll, to establish mills, and to make use of land for mill ponds, derived partly from the public and partly from individuals, either by purchase or by taking it, for public use, at an appraisement, by authority of the legislature. So far as this gave them a right to the use of land, it constituted an interest and qualified property in the land, not larger or more ample, or of any different nature, from a grant of land in fee, and did not necessarily withdraw it from a liability to which all the lands of the Commonwealth are subject, to be taken for public use, at an equivalent, when in the opinion of the legislature, the public exigency, or as it is expressed in case of highways, when pub lie convenience and necessity may require it. The plaintiffs still retain their franchise, they still retain all their rights derived from the legislative grants, and the only effect of the subsequent acts, is to appropriate to another and distinct public use, a portion of the land over which their franchise was to be used. We cannot perceive how it differs from the case of a turnpike or canal. Suppose a broad canal extends across a large part of the State. The proprietors have a franchise similar to that of the plaintiffs, to use the soil in which the bed of the canal is formed, and it is, in the same manner, derived by a grant from the legislature. It is a franchise. But if afterwards it becomes necessary to lay a turnpike, or a public highway across it, would this be a disturbance or revocation of the franchise and inconsistent with the power of the legislature in exercising the right of eminent domain, for the public benefit ? It might occasion some damagé ; but that would be a damage to property, and pursuant to the bill of rights, must be compensated for by a fair equivalent. It may be said, that the way might be carried high over the canal, and so not obstruct it. But suppose a rail road, a new erection, not contemplated when the canal was granted, and from the nature of which, it must be kept on a level, so as to subject the canal proprietors to considerable expense and trouble ; whatever other objections might be made to it, it seems to us, that it could not be considered as a *393revocation, still less an annihilation of the franchise of the proprietors.

If it is suggested, that under this claim of power, the legislature might authorize a new turnpike, canal or rail road on the same line with a former one to its whole extent, we think the proper answer is, that such a measure would be substantially and in fact, under whatever color or pretence, taking the franchise from one company and giving it to another, in derogation of the first grant, not warranted by the right of eminent domain, and incompatible with the nature of legislative power. In that case the object would be to provide for the public the same public easement, which is already provided for, and secured to the public, by the prior grant, and for which there could be no public exigency. Such a case therefore cannot be presumed.

If the whole of a franchise should become necessary lor the public use, I am not prepared to say, that the right of eminent domain, in an extreme case, would not extend to and authorize the legislature to take itj on payment of a full equivalent. I am not aware that it stands upon a higher or more sacred ground, than the right to personal or real property. Suppose, for instance, that a bridge had been early granted over navigable waters, say in this harbour, at the place where East Boston ferry now is, and the extension of our foreign commerce, and the exigencies of the United States in maintaining a navy for the defence of the country, should render it manifestly necessary to remove such bridge ; I cannot say that it would not be in the power of the legislature to do it, paying an equivalent.

Or suppose, as it has sometimes been suggested, that these dams of the plaintiffs, by checking the tide waters flowing through the channels below Charles River bridge, and through the harbour of Boston, should have so far altered the regimen of the stream, as gradually to fill up the main channel of the harbour and render it unfit for large ships ; suppose it were demonstrated, to the entire satisfaction of all, that this was the cause, that the harbour would become unfit for a naval station, or for commerce, by means of which most extensive damage would ensue to the city, to the Commonwealth, and to the eastern States, (for I mean to put a strong case for illustra*394tion,) would it not be competent for the legislature to require the dams to be removed, the basins again laid open to the flux and reflux of the tide ? I am not prepared to say that "t would not, on payment of an equivalent. But it is not necessary to the decision of this cause, to consider such a case, because, as before said, the act of the defendants does not, in any legal sense, annul or destroy the franchise of the plaintiffs.

Nor, in the opinion of the Court, is this exercise of power by the legislature, a law impairing the obligation of contracts, within the meaning of the constitution of the United States. A grant of land is held to be a contract within the meaning of this provision; and such grant cannot be revoked by a state legislature. This was held in regard to the revocation of grants of land by the State of Georgia. Fletcher v. Peck, 6 Cranch, 87. And yet there can be no doubt, that land granted by the government, as well as any other land, may be taken by the legislature in the exercise of the right of eminent domain, on payment of an equivalent. Such an appropriation therefore is not a violation of the contract by which property, or rights in the nature of property, and which may be compensated for in damages, are granted by the government to individuals.

The rights,‘by which individuals owning mills are enabled to flow the lands of proprietors of meadows, is essentially of the same character with that of the plaintiffs, and the main difference is, that the former are obtained by the operation of a general law, and the latter by a special act. But in the former case, the mill owners obtain an easement or franchise, not a property in the soil, and that, without and against the consent of the owners, upon high considerations of public expediency and necessity. But it seems to us, that it cannot be successfully maintained, that a rail road, canal or turnpike, could not be laid over such a pond, because it would diminish the capacity of the pond, and proportionably lessen the mill power. Forward v. Hampshire and Hampden Canal Co. 22 Pick. 462.

It is difficult, perhaps impossible, to lay down any general rule, that would precisely define the power of the government, in the exercise of the acknowledged right of eminent domain. It must be large and liberal so as to meet the public exigen* *395cíes ; and it must be so limited and restrained, as to secure effectually the rights of the citizen. It must depend in some measure upon the nature of the exigencies as they arise, and the circumstances of particular cases. In the present case, the Court are all of opinion, that the rights of the plaintiffs, in the land of the full and receiving basins, are not of such a character as to exclude the authority of the legislature, from taking a small portion of it, for laying out a rail road, it being for another and distinct public use, not interfering with the franchise of the plaintiffs, in any other way than by occupying such portion of this land.

But it is contended that the act in question is not valid, inasmuch as it does not provide a compensation for the damage done to the plaintiffs’ franchise. We are however of opinion, that this objection is founded upon the assumption already considered, viz. that the taking of a portion of the land over which the franchise extends is a taking of their franchise. The act does not take away the plaintiffs’ franchise, but provides foi taking part of the land, in which the plaintiffs have a qualified right of property. This is provided for in the first section of the act of incorporation, which directs that all damage occasioned to any person or corporation, by the taking of such land or materials, that is, land five rods wide, for the purposes aforesaid," shall be paid for, by the said corporation, in the manner thereinafter provided.

It has been held, that these provisions for taking land, and providing for an indemnity, are remedial and to be construed liberally and beneficially, and will therefore extend to leaseholds, easements, and other interests in land, as well as to land held by complainants in fee. Ellis v. Welch, 6 Mass. R. 246 ; Parks v. Boston, 15 Pick. 203.

Another ground much relied upon to show that the act is unconstitutional and invalid, is, that the act does not of itself appropriate the specific land taken, to public use, but delegates to the corporation the power of thus taking private property for public use, and therefore, the appropriation, or the right of eminent domain, is not exercised by the competent and proper authority, and that such power cannot be delegated.

This power is certainly one of a high and extraordinary *396character, and ought to be exercised with great caution and deliberation. This objection deserves and has received great consideration. On the whole, the Court are of opinion, that the act is not open to this objection. Taking the whole acts of incorporation together, we are of opinion that it sufficiently declares the public necessity and convenience of a rail road, fixes the termini, viz. in or near the city of Boston and thence to any part of Worcester in the county of Worcester, in such manner and form as the corporation shall think most expedient Nothing therefore is delegated to the corporation, but the power of directing the intermediate course between the termini The question ■ of necessity for public use is passed upon and decided by the legislature. Whether the road goes over the lands of one or another private individual, does not affect that question. So far as the objection is, that the power is delegated to the corporation instead of being exercised by county commissioners or any other public body, it is rather a question of propriety and fitness, than one of power. In the present case we think that the interests of the corporation and those of the public, were so nearly coincident, it being plainly for the advantage of both that the shortest, safest and cheapest route should be chosen, that the power might be safely intrusted to a corporation thus constituted. This mode of exercising the right of eminent domain, is warranted by numerous precedents, both in our own Commonwealth and in most of the other States of the Union.

We are then brought to another and very important inquny, which is this ; supposing the legislature has a full and constitutional authority to pass an act, empowering the defendants to lay out their rail road over the land used by the plaintiffs, whether they have in fact granted any such power. This must depend upon the construction of the act of incorporation, applied to the subject matter, both of the contemplated rail road, and the existing works of the plaintiffs. The latter contend that their works were contemplated to be works of public utility, and upon that ground they were authorized to take part of the public domain, and under the authority of the legislature, to take the property of individuals, which would have been inadmissible on any other ground. Boston and Roxbury Mill *397Dam Corp. v. Newman, 12 Pick. 467. They therefore insist, that as the lands had been already appropriated to public use, by the grant to the plaintiffs, it could not again be appropriated to the defendants by a subsequent act. So far as this affects the power of the legislature, it has already been considered. It was another and distinct public use, growing up after the former appropriation, and which might be reached, without defeating or essentially impairing the public use, to which it had been already applied.

It is therefore a question bearing upon the presumed intent of the legislature. It may be fairly argued, that though there is no limitation of the power of the corporation in terms, still if the legislature had already apprópriated a portion of the land lying between the termini, to another important public use, and especially if the construction contended for would wholly, or in, a great degree, defeat such other important public use, it is not to be presumed that the legislature meant thus to extend the power, and so a limitation might be engrafted, by necessary and reasonable implication, upon the generality of the act.

The terms of the act (St. 1831, c. 72,) are certainly broad enough to include the power to take this land and pass over the full and empty basins of the plaintiffs. The first section authorizes the corporation to locate, construct and finally complete a rail road, in or near the city of Boston and thence to any part of Worcester. The third section authorizes the president and directors for the time being, by themselves or their agents, to exercise all the powers granted to the corporation for the purpose of locating, constructing and completing the rail road. Their location is to be filed with the county commissioners. The president and directors of this corporation, therefore, are authorized to locate the rail road, between the termini, that is, to determine in what particular direction it should pass between the termini. To this extent they were to exercise their own judgment. And the Court are of opinion, that there is nothing in the nature of the plaintiffs’ public works, or in the public use to which they were applied, and the extent to which that use would be impaired or diminished, by the taking of such part of the land as might be necessary for the location of this rail road, from which the power, of locating the *398rail road over it, may be presumed to have been restrained bj the legislature. Both uses may well stand together, with some interference of the later with the earlier, which may be compensated for by damages. In this respect, therefore, it differs from many of the cases put, where it is asked whether one canal, turnpike, or rail road,, may be laid over the same line with a former one. Both cannot stand together, and one must supersede the other. And this shall not be construed to be the intent of the legislature, unless it appears by express w-ords or necessary implication. In this respect, also, this case differs from the case in Gill and Johnson. There the canal and the rail road must necessarily occupy the same identical line, each for a public use ; both could not stand together, and therefore it was decided, that a franchise already granted should not be considered as superseded and taken away by a subsequent legislative act, granting power in general terms.

So, if a power were given in general terms, to lay out a turnpike or rail road between termini definitely expressed, such general power ought not to be so construed as to take an arsenal, fort, state-house, or land already appropriated to a highly important public use, which would be defeated by such construction. It would be a question of legislative intent; and it could not be presumed, that the legislature intended that the power conferred by them should have such an effect, unless it were unequivocally expressed.

It was, however, contended, that the defendants were ex pressly restrained from building a bridge over the waters of Charles river, and although by a subsequent act they were author ized to build a bridge over Charles river, yet it was limited to be between the Western Avenue and Canal Bridge, and therefore, did not take away the first prohibition, so far as to build over the waters of Charles river, south of the Western Avenue, where they have in fact located the rail road. The words of this fifteenth section are, that nothing contained in this act shall be construed as giving the Boston and Worcester Rail Road Corporation authority to. erect a bridge over the waters of Charles river connected with the city of Boston. The natural and obvious meaning of this is, over Charles river, or - across Charles river, that is, the bed or body of the river from one *399snore to the other, and not along the margin of the river. Any other construction would restrain them from building over a cove or creek adjoining to and connected with the river, which, to many purposes, may be considered the waters of Charles river ; but such a restriction, we think, could not have been contemplated. This construction is strengthened by the consideration, that the subject of obstructing the navigation of Charles river, by bridges across the same, had been agitated before the legislature with great earnestness for several years before this act passed.

But there is another view of this subject, which seems quite decisive, which is this; whether or not the waters over which the rail road has been built, may have been considered the waters of Charles river, before the dams of the plaintiffs were erected, we think they had ceased to be so, and could not have been so considered and intended by the legislature, after they had been penned up and enclosed by these dams, and thus effectually separated from the river, which was done a long time before this act passed. We are, therefore, of opinion, that the prohibition to build a bridge over the waters of Charles river, as used in this act, did not prohibit the defendants from locating their road on these full and receiving basins, by means of a bridge or causeway, but was intended to apply to the waters of Charles river then open to navigation, and mainly to protect that navigation.

The Court are of opinion, upon the whole case, that the legislature had the constitutional power, to a limited extent, to exercise the right of eminent domain over the lands used by the complainants as their full and receiving basins, providing in the act suitable measures for making compensation to the complainants, if they sustained damage thereby ; that the act did make such prov'sion ; that the power of the legislature was well executed, in declaring the general purpose and exigency of appropriating private property for public use, by establishing a rail road within certain termini expressed, and by granting to a corporation, established and constituted as the defendant corporation was, the power of determining the particular course and direction of the rail road between those termini ; that the defendants were not restrained, by express words, or any *400necessary, just, or reasonable implication, from laying out their rail road as they have done, over the basins used by the complainants under their franchise, and therefore, that the averment of the complainants, that the rail road is laid over their basins without any just and lawful authority, and is consequently a nuisance, is not supported.