The form of the petition is supported by precedent. Some of the cases in which it has been used, without the question of its sufficiency being raised, were strenuously contested. But if it is not a statement of a controversy that can be settled in a suit of this nature, or if on any point of the public claim presented by the plaintiff it does not contain such information as he ought to give, mere precedent does not authorize an infringement of the defendant's substantive or remedial right. The mill act requires "reasonable notice to all persons interested," and provides a method, and a convenient and ample remedy, for an exercise of the public power of eminent domain, that may relieve all persons interested from other litigation on questions of title, tort, and damage. The defendant is entitled to compensation neither for damage that is not to be done (Town v. Faulkner, 56 N.H. 255), nor for damage to be done to land in which he has no interest, nor for all the damage to be done to land in which his interest is less than the whole title. His title is presumed to be peculiarly within his knowledge; and the plaintiff needs to allege concerning it only what he understands the defendant claims. The statute, construed to accomplish its purpose of ascertaining and establishing a public right in a manner that will inflict no injustice upon either party, does not make it necessary that the plaintiff should either admit a title or a flowage that is disputed, or take a course that would expose him to a preliminary lawsuit. The height of his proposed obstruction of the water is peculiarly within his knowledge, and should be averred and proved by him; and he should *Page 527 furnish all evidence that can reasonably be demanded of him on every question raised by his assertion of the public right to maintain the obstruction. If he admits the defendant will be injured, he should offer proof of the amount of damage. If he denies either title or injury, he should offer such proof as can reasonably be expected from one who affirms such a negative. It is for the court at the trial term to require the plaintiff's performance of the duty he must assume, and to see that the defendant's right of property is not violated by expense wrongfully thrown upon him. The procedure is thoroughly equitable. Either party may be plaintiff. If the defendant had brought the petition, neither party would have been obliged to admit what equity would require his adversary to prove; and the merits of the case are not reversed by the circumstance that the defendant does not ask that determination of the rights of both parties to which each is entitled.
The entire line of a proposed flowage is generally one that cannot be easily marked on the ground, as the bounds of a proposed railroad or other highway may be. Its most accurate and satisfactory description is often based on the height of the dam, or an altitude fixed at some other place. Town v. Faulkner, 56 N.H. 255, 259, 261. The contracts in W. L. Co. v. Perley, 46 N.H. 83, and S. F. Co. v. P. Co., 46 N.H. 249, 250, 251, 252, are instances of the common practice of adopting a certain level as the most expedient boundary in a conveyance of a flowage right. On payment of the price, a judgment authorizing the plaintiff to flow the defendant's land for public use would be an involuntary conveyance, in which the description of the premises might be such as the parties would probably employ if the conveyance were made without compulsion, and were limited to so much land as is needed. One inquiry may be, whether the flowing of the land "to the depth and extent that the same may or can be flowed by said dam, is or may be of public use." No more can be taken than "is necessary for the use of the mill or mills" for which the dam is designed. For the purposes of the land-owner, the flowing capacity of the dam may be the most useful description of the public claim; and it may be the only practicable measure of what can be taken. This petition does not show that the defendant needs, or that the plaintiff can equitably be required to propose, any other measure. A specification can be ordered at the trial term, if justice requires it; but the public right is not to be unreasonably obstructed by orders not necessary for the defendant's protection.
Demurrer overruled.
CARPENTER, J., did not sit: the others concurred. *Page 528