This section is from the book "Popular Law Library Vol7 Equity Jurisprudence, Trusts, Equity Pleading", by Albert H. Putney. Also available from Amazon: Popular Law-Dictionary.
5 11 Colo., 494; 19 Pac, 471.
"From this review of the cases cited, it will be seen that they have no application to the case at bar. In the case under consideration there is no question but that it was the intention of the plaintiff to purchase the identical 22 feet of ground on which the building she occupied stood. The defendant so understood the intention of the plaintiff, and he supposed that the conveyance made by him covered the premises the plaintiff intended to buy. The mutual mistake made by the plaintiff and defendant was in relation to a material fact, and but for the fact of the mistake the plaintiff, certainly, would not have entered into the contract from which she seeks to be relieved, and it is but just to the defendant to presume that he would not have taken the plaintiff's money without intending to give her value therefor. It does not appear that there are intervening rights to prevent the parties from being placed in the same position they were before the contract was made. In 1 Story, Eq. Jur., 138, it is said to be the clearly defined and well established rule, both in England and America, that under such facts as are established by the evidence in this case equity will interfere, in its discretion, in order to prevent intolerable injustice. In illustration of the doctrine that equity will relieve in such cases, the learned author states the following supposed case: 'If one person [should sell a messuage to another, which was at the same time swept away by a flood, or destroyed by an earthquake without any knowledge of the fact by either party, a court of equity would relieve the purchaser, upon the ground that both parties intended the purchase and sale of a subsisting thing, and implied its existence as the basis of their contract. It constituted, therefore, the very essence and condition of the obligation of their contract.' 1 Story, Eq. Jur., 142. Under the facts of this case we do not conceive that the question of negligence arises; but, if it is in the case, the evidence does not show such a state of facts as should prevent the plaintiff from obtaining the relief demanded. At the time of making the contract the plaintiff was paying rent to the defendant for the premises she desired to purchase, and the defendant was receiving such rent as the owner of the premises. The plaintiff had the right to assume that defendant was the owner of the premises, and to act upon such assumption. 1 Story, Eq. Jur., 140; 2 Pm., Eq. Jur., 856; Quick vs. Stuyvesant, 2 Paige, 84-92. We therefore conclude that the plaintiff made a case which entitled her to the relief demanded."
It was held in Lawrence vs. Staigg,6 that a mistake as to the quantity of the land conveyed by a deed is a mistake relievable in equity.
'The facts stated and proved in this case are that the plaintiff arranged for sale and sold, through the agency of Alfred Smith, a well-known real estate agent in Newport, a portion of a certain farm belonging to the plaintiff, called the Ochre Point Farm, in said Newport. That Smith, who had the sole direction and control of said sale, in the summer of 1862 employed a surveyor by the name of Samuel S. Minot, reputed for his skill, to survey the portion of said farm to be sold into lots, and measure and plot the same, to be sold by one Swinburn, by auction. That among the lots so measured and plotted was lot No. 1 on the plot of said lots, set down as containing 45,918 feet to high water, by mistake of said surveyor, when, in truth, and in fact, said lot contained, in its true area to high water, 55,680 feet. That said lot was sold by auction, through mistake, to the defendant, and by him bought, as containing said area of 45,918 feet, instead of its true area of 55,680 feet, at five and one-quarter cents per square foot, and upon receiving a conveyance from the plaintiff of said lot, the defendant paid his said agent, Smith, the sum of $755.69 and delivered to him a mortgage for the payment of a note of $1,550, in three years, with interest, the area and price of said lot being adjusted by and according to said mistake. The bill prays that the sale, made as above, by mutual mistake as to area, may be rescinded, the consideration being returned to the defendant, and the land reconveyed by him to the plaintiff.
5 8 R. I., 256.
"We are clearly of opinion that this equity demanded of the defendant is due, under the facts, to the plaintiff, there being no doubt that the sale and conveyance were made under a mutual mistake, as to the area sold, and the price justly to be computed as the price of the lot. No fault or neglect in the matter is fairly imputable to the plaintiff, who employed an agent to arrange the sale of his farm, of skill and good repute. This agent, for the purpose of surveying, measuring and plotting the lots to be sold, including lot No. 1, sold under the above mistake to the defendant, employed a skillful civil engineer, who, in performing his duty, fell into the mistake as above mentioned, which has caused the parties to contract and execute their contract of sale, contrary to the design and against right, as due to and from both parties. The sale, like that in Leslie vs. Thompson, was made according to the report of a surveyor, which was incorrect, and the contract was, as in that case, entered into under a mistaken conception of the amount of the property comprised in the particulars embraced in the report. There is no pretense, under the fact proved, that the plaintiff designed or expected to sell lot No. 1 in the mass or lump, or that the defendant designed or expected to buy it in that mode. The designation of the number of feet in the tract, with the price per foot at which it was sold, negatives any such presumption. In the exercise of its jurisdiction over the subject of such a mistake, the court will require, what it finds in this case, full and satisfactory proof of the mistake, and will be of little value, if it can suppress only positive frauds, and leave a material mistake, like the one in this case, innocently made, to work on intolerable mischief, contrary to the intention of the parties. As we have already had occasion to repeat, in the language of Judge Story: 'It would be to allow an act originating in innocence to operate ultimately as a fraud, by enabling the party who receives the benefit of the mistake to resist the claims of justice, under the shelter of a rule framed to promote it.'
"According to the well-settled principles of equity jurisprudence applicable to such a subject, we must rescind the contract and sale entered into and arranged by mistake in a substantial particular, and which, if suffered to remain, will work a fraud upon the plaintiff, unless the same be confronted to the truth and fact in the particular complained of."