In this case the complainant, on the twenty-ninth of March, eighteen hundred and thirty-four, leased to the defendant a saw mill in Trenton, for the term of four years and ten months, at a rent of four hundred and forty-six dollars, including the privilege of drawing from the canal of the water-power company, for the use of the mill, a quantity of water equal to “ six horse power,” without any description of what quantity of water, at that situation, was to be considered as “ a horse power.”
The bill charges that the complainant had made a verbal agreement with William G-. Cook, the brother of the defendant, for a lease of the same mill, by which it was agreed that he should pay by way of rent sixty dollars for the lot, ten per cent, upon the cost of the mill, and three dollars per square inch for the water, and that this lease was made with reference to that verbal agreement, and the rent adjusted accordingly. And the bill further charges that it was the universal understanding with the mill-owners and with the water ¡sower company, that at this situation, with the head and fall of water which existed there, nine square inches were equal to a horse power, and that this lease was made with that understanding both og the part of the complainant and defendant.
In conformity with this understandinn,the complainant, in adjusting the aperture to discharge the water on to the wheel of the mill, fixed it at fifty-four square inches, equal to a six horse power at nine inches per horse power. The defendant removed this aperture, and put another aperture equal to seventy-two square inches and claims a right to draw from that aperture ; and to restrain him from drawing more water than would flow through an aperture of fifty-four square inches is the principle object of the bill. The defendant, in his answer, denies that the lease was made in conformity with the verbal agreement which had been made with his brother, or that in making the lease, nine square inches were considered as a horse power, and alleges that he refused to execute any agree men tun til the rent could be fixed and made certain as to amount; that he was informed by *113the engineer that a six horse power would be sufficient to drive the mill, and that the terms were used in the lease in their technical sense; that he did not know what aperture would give a horse power, and that after the lease was executed he understood that an aperture of nine square inches would give a horse power.
Erom the evidence in the case, it is manifest that it was the general impression among those interested in the water power and mills and property upon it, that it would require an aperture of but nine square inches at this location to give one horse power, and it is equally manifest that this impression arose from a mistaken calculation of the engineer, and that in point of fact it required an aperture of twelve square inches at that location to give a horse power. It was not a mistake as to the extent of a horse power, according to its technical meaning, but the mistake arose in calculating the extent of an aperture which would yield that power.
If the complainant would limit the defendant to the measurement of an aperture of nine square inches for a horse power, it would be necessary for him to show, not only that such was the general impression, but he must show that the defendant agreed to this manner of measuring the horse power. It would not be sufficient to prove that even the defendant himself, at the time of the lease, was under the impression that an aperture of nine square inches would yield a horse power, for he might have had that impression and yet been unwilling to make a contract upon it.
What is the evidence as to this point ? The bill alleges, that the lease was made with reference to this parol agreement with the brother, whereby the rent was adjusted at three dollars per square inch. The answer expressly denies this part of the bill, and upon this answer the defendant may rest, unless there is evi dence to contradict the answer in this respect.
Upon examining the testimony I cannot find tñat this allegation of the answer is contradicted ; on the contrary it appears to be confirmed by all the testimony which applies to this point.
*114A lease was made out by Mr. Lott, which was in conformity with this verbal agreement of the brother, fixing the rent at sixty dollars for ground rent, ten per cent, on cost of mill, and three dollars per inch for the water. This lease the defendant refused to execute, because the amount of rent was uncertain. The lease now in dispute was then made out by Mr. Evans, which was executed, and at the time this lease was executed Mr. Evans says that “ something was said about a lease having been drawn by Mr. Lott, but never had been executed. Mr. Cook said he did not like it.”
This evi dence is in confirmation of the defendant's answer, and shows that he would not make the contract until the amount of the rent was settled and fixed. From information derived from the engineer, he knew or believed that a six horse power was sufficient to drive the mill, and therefore was willing to contract for a six horse power, but was not willing that the rent should be uncertain, and therefore refused to sign the first lease, which was uncertain as to the amount of rent, both as respects the ten per cent, upon the cost and the three dollars per square inch of water that might be required to drive the mill.
In this stage of the negociation I presume that the complainant undertook to establish in his own mind what rent he would charge, and in adjusting it he set down sixty dollars for ground rent, then ascertained the cost or probable cost of the buildings, and took ten percent, of that cost for the next item, and then, being under the impression that nine square inches would give a horse power, and as the defendant wanted a six horse power, he made his calculation upon fifty-four square inches of water, and thus made up the amount of four hundred and forty-six dollars as the rent of the whole; and the defendant agreed to this amount, and the lease was accordingly executed. But it turns out that the complainant was mistaken in his impression that nine square inches would make a horse power at that place, and that it in fact requires twelve square inches to give that power. If under these circumstances it should be admitted by the defendant that he was under the impression at that time, that an *115aperture of nine square inches at that place would give a horse power, I can see no reason why he should suffer for the mistake. He would not take upon himself the risk of these impressions being correct. He undoubtedly intended to bargain for enough water to drive the mill, and satisfied himself that a six horse power would do it, and there is no evidence that he agreed as to any particular manner of measuring the quantity -of water that would yield that power.
In order to test the principle, let it be supposed that the mistake had been the other way, and that in fact six square inches at that place would have given a horse power, and the defendant had insisted that his rent should be received in that ratio, he would have been told that the water was offered to him by the inch, but that he would not take it so, and insisted upon having the rent fixed at a sum certain.
Again, supposing it had turned out that the complainant had made a mistake in estimating the cost of the mill, and instead of costing him two thousand two hundred and forty dollars (as alleged,) ;.t had cost him three thousand two hundred and forty dollars, thereby making a difference in the rent of one hundred dollars (according to the views of the complainant,) could he with propriety have called upon the defendant to pay the added rent •of one hundred dollars upon discovering this mistake ? I apprehend not; in either case the mistake was made by the complain,ant and he must suffer the loss in consequence of that mistake.
I am therefore of opinion that the defendant, by virtue of his lease, is entitled to draw a quantity of water equal to a six horse power, and to use an aperture which will yield that power. As to the allegation that the mill is injured by the use of too much water, and thereby driving it too fast, if it was a case for the interference of this court there is no evidence of such continued or threatened irreparable injury as to authorize the exercise oi its power. Let the bill be dismsssed, with costs.
* Decree accordingly.
An appeal having been taken by the complainant, this decree was unanimously affirmed, with costs, by the court of appeals, at a special term, in January, eighteen hundred and forty.