Sawyer, J.
It may be assumed, that, by the release of September 8, 1843, executed by two of the plaintiffs, and the assent of the other two to the arrangement, with the defendants, as therein expressed, the Eastern Bailroad was licensed, or otherwise authorized to maintain and use their bridge as it then was, and were also empowered to modify the structure at any future time, in any way that the purposes of the corporation might require. No question is made, and there is perhaps no ground for raising a question, that the change in the character of the structure, from a bridge, supported on piles, to a solid embankment of earth, was such a modification of the structure as to come fairly within the meaning of the terms employed in the release. The release acknowledges the receipt of one hundred and forty-five dollars as the consideration paid therefor; and it contains, in addition, a recital in the preamble, that that sum, it was agreed, was to be received in full for all damages which had been occasioned by the construction of the bridge, and for any future damages which might arise from a modification of it. There is, however, a provision contained in the body of the release, that if the present structure shall be so altered as to increase the damages, by diminishing the quantity of water in the mill-pond, or impairing its efficiency, the plaintiffs are not to be prejudiced in their further claim for *162the additional damages beyond the sum agreed upon. It is clear that the construction to be given to the instrument, upon a view of all its terms, is that the plaintiffs acknowledge satisfaction of all damages, past and prospective, arising from the bridge as it then was or as it might be by reason of any change of the structure, excepting only such additional damages as the alteration might occasion in diminishing the quantity of water, and impairing the efficiency of the pond to operate their mill. The release was not to prejudice their claim for these additional damages. All other damages which the alteration might occasion, as well as all which the bridge had caused, or might thereafter cause, in its then condition, were released, and the sum received in consideration of the release was paid in satisfaction of these damages. For the damages resulting from any future modification of the bridge, in diminishing the quantity of water, or impairing the efficiency of the pond, and for these only, the plaintiffs stipulated for further compensation, the amount of which was left indeterminate. If, then, without the grant by the plaintiffs of any further right, the defendants had proceeded to make the alteration, by substituting the solid embankment as the foundation for their superstructure, in place of the support by piles, and thereby further damages had been occasioned to the plaintiffs, in diminishing the capacity of the pond, or otherwise impairing its efficiency, the plaintiffs would have been entitled to further compensation, commensurate to the additional damages. And it is not perceived what remedy they would have had for recovery of that compensation, except by action of assumpsit upon the implied promise to pay such sum as might be a just remuneration for the injury. Whether the transaction might be regarded as a license by the plaintiffs to make the alteration, or whether it might he considered as amounting to a grant of the right — as upon a contract for a valuable consideration — in either view it was made *163upon the express condition that the plaintiffs should be entitled to claim the additional compensation. The defendants, in exercising the right without further authority from the plaintiffs, must have been held to agree to the condition proposed. If the right to make the alteration rests upon the release executed by two of the plaintiffs, and the assent of the others to the arrangement therein expressed, the right must be exercised in conformity with the terms of the arrangement; and in the proceedings it is clearly implied that if the defendants choose to avail themselves of the right which it gives, they shall make just compensation for the additional damages. Having exercised the right upon that understanding, the promise to pay, sufficient to support the action of assumpsit, is implied.
Assuming, then, for the present, that the authority of the defendants to make the alteration is to be found only in the transaction of September, 1843, upon the facts stated, it is manifest that the plaintiffs may have sustained the additional damages contemplated. Their mill is operated mainly by tide-water. The supply of water received into the pond at each flood is exhausted by operating the mills upon it at each ebb. It is the right of the plaintiffs to operate their mill until the pond is drawn' down to a designated point; and this it is stated usually occurs at about half tide. They may then be required to suspend. It is obvious, therefore, that any cause which has the effect to contract the capacity of the pond, thereby diminishing the volume of water to be discharged during the ebb tide, must have the effect to abridge the time they may have the right to run their mill at each ebb, and thus to a greater or less extent impair its value.
There can be no doubt that the solid embankment, in place of the support by piles, diminishes the capacity of the pond and the volume of water; whether or.not to an appreciable extent, and to the damage of the plaintiffs, are *164facts not stated in the report. If these facts exist, the plaintiffs’ right of action under that arrangement is clear. The question then arises, whether they have barred themselves from the right by any proceeding subsequent to the arrangement of September, 1843.
By their deed to the Portsmouth and Concord Railroad of the 8th of May, 1849, they released and quitclaimed a portion of the mill-pond described by definite boundaries. The release was executed before the acts complained of; and consequently, so far as those acts were confined to the limits of the premises released, the plaintiffs have no right to compensation for the loss of the water of the pond to the extent of those limits, unless it be in virtue of some exception or reservation to that effect, contained in the deed. Under this deed the grantees — the Portsmouth and Concord Railroad — as to these plaintiffs are to be considered the owners in fee of the territory included within the boundaries of the premises released, and they embrace, with other land, that also upon which the bridge stood as it was then constructed. The quitclaim by the plaintiffs of all right to a portion of the pond, marked by definite boundaries, leaves them at least no ground upon which to question that the party to whom they have released is entitled, as the owner, to occupy and enjoy the land in as full and ample manner as in the case of any owner of the fee under a deed of warranty, unless restrained by some provision contained in the deed. The description is of a part of the mill-pond. By the term ‘pond,’ the land covered with the water of the pond passes. In Co. Lit. 5, it is said, “if a man grant aquam suam, the soil shall not pass; but by the name stagnum — a pool, the water shall pass, and the land also. So gurges — a gulf, is water and land; and therefore by grant thereof by that name the soil doth pass.” The word pond is as effectual to pass the soil as pool or gulf.
*165The Portsmouth and Concord Railroad, then, had the right, unless so restrained, to fill up- the pond through the whole extent of the portion released, including the ground occupied by the bridge; and they could convey to others, as against the plaintiffs, the title to the whole or any portion of the premises released, and with it the same right of raising the whole or any portion of the surface above the flow of the tide. This they did by their deed to the defendants of May 8, 1850, to the extent of the ground covered by the bridge in its then condition.
The question, then, to be considered is, whether the release from the plaintiffs to the Portsmouth and Concord Railroad contains any provisions limiting the rights which ordinarily attach upon a conveyance in fee, in the use and enjoyment of the land conveyed, and restraining them from filling up that portion of the pond occupied by the bridge. If they are not restrained, their grantees — the defendants — are not. The clause in the deed, which, it is claimed by the plaintiffs, amounts to such restriction, is in these words: “ Saving, excepting and reserving all rights, titles, interest and privileges which have been heretofore by us, or any or either of us, conveyed to said Eastern Railroad.” The rights and privileges here intended must be understood to be the right to maintain the bridge, and the right to modify it in any manner which the purposes of the corporation may require, upon making compensation to the plaintiffs for the actual damages. These rights, it may be conceded, had been conveyed by the plaintiffs to the defendants, and were thus within the terms of the exception; and the Portsmouth and Concord Road were consequently restrained from any use or enjoyment of the premises which would violate or impair the rights reserved to the Eastern Road. But they would be restrained no farther. These rights merely constituted an easement, and the Portsmouth and Concord Road took the estate subject to it. They were at liberty to devote *166the land to any use, or occupy it in any way which would leave to the defendants the use of their bridge, and the privilege of modifying it as they might find occasion; and with their rights in this respect the filling up of the pond by the Portsmouth and Concord Road would have interfered in no way to which they could object. The substitution of a solid embankment for the water of the pond under the bridge, would not have interrupted the easement, nor rendered them less able to exercise the right of altering the bridge. If the purposes of the Portsmouth and Concord Road had required it, for their convenient use of the premises, they might have proceeded, even against the will of the Eastern Road, to make the embankment, within the limits of the premises released, precisely as it was made by the defendants; for it would not have been inconsistent with the enjoyment by them of their easement. If they could do it under the deed from the plaintiffs, they could empower the defendants to do it, also, by conveying the premises to them.
But if the Portsmouth and Concord Road should be held to be restrained from making the embankment, as against the Eastern Road, because it would be inconsistent with the enjoyment of the easement, still the plaintiffs have no claim for compensation, so far as relates to acts confined to the land released, upon other grounds, arising from the nature of the exception.
If any right is reserved to the plaintiffs under the clause in question, it is either because it in effect excepts some part of the thing granted from the operation of the grant, so that it does not pass by the demise — thus constituting a technical exception in the deed — or because it creates and reserves to the grantor a new right, not before in esse, and not a part of the thing granted, but springing from it, like rent or an easement reserved, and thus constituting a technical reservation.
*167In 1 Shep. Touch. 77, an exception is'defined to he a clause in the deed whereby the grantor excepts somewhat out of that before granted; and it is said eveiy exception must be of part of the thing granted, capable of being severed from it, and not an inseparable incident; and “ such that he that doth except may have, and doth properly belong to him.” Instances given are a grant by one 'of all his lands in Essex, except or saving his lands in Dale, or all his lands in Dale, except a certain house. A reservation is said, p. 80, to be a clause whereby the grantor reserves some new thing to himself out of that which he has granted, but not part of it, nor a thing in esse, until created by the reservation. Such are a right of way, of fishery, or other incorporeal right, created at the time of the grant, and reserved to the grantor out of the land. In Co. Lit. 47, (b,) it is said, “ Note the diversity between an exception which is even part of the thing granted, and of a thing in esse, and a reservation, which is always of a thing not in esse, but newly created, or reserved out of the thing demised.” The distinction is recognized in Cocheco Manufacturing Co. v. Whittier, 10 N. H. 305; Thompson v. Gregory, 4 Johns. 81.
If the clause, then, is to have the effect to retain to the plaintiffs, as against the operation of the quitclaim, the right to recover damages for filling up the pond beneath the bridge, it must be either because the land covered by the bridge is intended tobe excepted'in the use of the terms, — 1 excepting the rights, titles, interest and privileges conveyed to the Eastern Hoad’ —thus giving to the clause the character of a technical exception, exempting this land from the demise, or because it creates a new incorporeal right in the grantors, arising out of the land, not before in esse, like rent reserved, the easement of a way, or the like; and which, in this case, can be only the rights to modify, maintain, and use the bridge so modified. Either construction is alike inadmissible. To construe *168the clause as an exception reserving the land, would be in effect to hold that a clause in a deed of land, with an existing public or private way upon it, excepting the way, would reserve to the grantor an estate in fee in the land occupied by the way. To construe it as the reservation of an easement would convert the easement described in the excepting clause as an existing right in the Eastern Railroad .into a new easement, thereafter to be held and enjoyed by the grantors. If the conveyance to the Portsmouth and Concord Road had been by deed of warranty, with the usual covenant against incumbrances, it would be manifest that the object and effect of the clause would be merely to except the easement from the operation of the covenant. In a naked quitclaim it may perhaps have the effect to impart notice to the grantees of the claim, of right made by the Eastern Road to maintain, modify and use the bridge, and of the transactions of 1843, upon which their claim is founded, and thus to secure them in equity, perhaps in law, against the interruption of the easement by the Portsmouth and Concord Road. It can have no effect and operation beyond this. Thus far the discussion has proceeded upon the assumption that the acts of the defendants in making the embankment were confined to the limits of the premises described in the release, and for these acts the plaintiffs have no claim for damages. But if, in filling in for the embankment, or otherwise modifying the structure of the bridge, they have passed beyond those limits, and thereby damages have been occasioned, the right of the plaintiffs to compensation rests upon the implied agreement to pay, under the arrangement of 1843; and as to these damages they have done nothing to bar themselves from maintaining this action therefor.
The boundary of the premises is described as the northerly side line of the bridge. By this must be understood the bridge as it was at the time of the conveyance. It is *169described as constructed of timbers placed as stringers lengthwise of the road, upon transverse caps, resting on piles, and projecting on each side of the road some inches beyond the stringers. The projecting ends of the caps constituted the extreme points of the bridge laterally. A line from cap to cap on the northerly side of the bridge, touching their projecting ends, and continued to the eastern shore, would have left all parts of the foundation and superstructure upon its southerly side. Beyond this line there was nothing to indicate a limit as the northerly side line. The premises released are therefore bounded by that line. For any diminution of the capacity of the pond by the material placed in it beyond this boundary, in making the embankment and occasioning actual damages to the plaintiffs by impairing the use of their mill, the defendants are liable. This is to be determined upon an inquiry into the damages by the jury, or by an auditor, as provided in the case transferred.