estoppel by silence are quite numerous, and many of them may be found in the cases cited in the note.' But silence will not always work an estoppel, for a person is not bound, under all circumstances, to speak out.2 He may not, for example, be bound to declare that which is a matter of record, and of which he has a right to presume the other party has notice.3 285. Estoppel by conduct must consist in something which is external to the contract or transaction. To explain: the obligor in a bond may have a good defence to any action on the instrument by reason of its having been obtained by fraud or duress. Such obligor might be estopped from setting up such a defence against an innocent assignee, if the assignment had taken place upon the faith of his assertion that no defence existed. That would be an estoppel, and it would arise out of something external to the contract. But if no such assertion had been made, but the assignee were simply to argue that the obligor of the bond was estopped by the recital contained in the bond that "he was justly indebted" from showing that in fact he was not justly indebted, such an argument would be unsound, because, in that case, the estoppel would be attempted to be founded upon something in the contract itself, and this cannot be done. The reason of this distinction is simply that if the very words of a contract are to be taken as a representation of facts, which estops the party who makes the obligation from interposing a defence inconsistent with that representation, then all contracts must be deemed valid which appear to be so on their face, and 1 Hope v. Lawrence, 50 Barb. 258; Blake v. Exchange Ins. Co., 12 Gray, 265; Hoxie v. Home Ins. Co., 32 Conn. 21; Cambridge v. Littlefield, 6 Cush. 210; Ford v. Williams, 24 N. York, 359; Gregg v. Von Phul, 1 Wall. 274; Hill v. Epley, 7 Casey, 334; Abrams v. Seale, 44 Alab. 297; Guthrie v. Quinn, 43 Id. 561; Ives v. North Canaan, 33 Conn. 402; Smith v. Smith, 30 Id. 111; Newell v. Nixon, 4 Wall. 572; Weber v. Weatherby, 34 Maryl. 656; Fletcher v. Holmes, 25 Ind. 458; Stagg v. Insurance Co., 10 Wall. 589; Silloway v. Neptune 2 See Corning v. Troy Factory, 39 Barb. 311; 40 N. York, 191; Shaw v. Spencer, 100 Mass. 382; Watson v. Knight, 44 Alab. 352; Hopper v. McWhorter, 18 Id. 229; Taylor v. Ely, 25 Conn. 250; Spencer v. Carr, 45 N. Y. 406; Elliott v. Ins. Co., 16 P. F. Sm. 26. Rice v. Dewey, 54 Barb. 455; Bales v. Perry, 51 Missouri, 449. neither usury, nor duress, nor fraud, could any longer be alleged in defence.1 286. The representation which works an estoppel may sometimes take place in a transaction effected between the party alleging the estoppel and the party estopped. In other words, the parties to the transaction and the parties to the estoppel may be the same. Under this doctrine fall those cases in which a defence to a contract, which might otherwise have been taken, has been waived by the conduct of the party. Thus a common instance is found in the cases in which insurance companies have been held incapable of raising objections to the sufficiency of preliminary proofs of loss, because they have by their conduct dispensed with the requirements of their policies.2 287. On the other hand, the representations which give rise to an estoppel may occur in a transaction which takes place between the party alleging the estoppel and some third party; in other words, the parties to the transaction and to the estoppel may be different. This embraces by far the largest class of estoppels by conduct, and is a species of estoppel which receives its greatest encouragement in courts of equity, and, therefore, most strictly deserves the term of equitable estoppel. Under this head fall the case of Pickard v. Sears,3 cited above, and all those numerous cases in which a party is prevented from asserting his title, because, by active encouragement or equally effective silence, he has induced third parties to believe that no such title exists, and they have expended money, or in some way altered their position on the faith of such supposed non-existence. Thus, it has been often held, that, where the owner of real estate encouraged another to erect valuable improvements upon the land, he was precluded from subsequently asserting his title.* So, if the owner of an estate stand by and see another expend money upon an adjoining estate, the latter relying upon an existing right of easement in the other estate, without which Clark v. Sisson, 22 New York, 312; Bigelow on Estoppel, 480. 2 Blake v. Exchange Ins. Co., 12 Gray, 265; Hoxie v. Home Ins. Co., 32 Conn. 21; Bigelow on Estoppel, 503. 3 6 Ad. & El. 469. Leeds v. Amherst, 2 Phillips, 117; Favill v. Roberts, 50 N. Y. 222; Storrs v. Barker, 6 Johns. (Ch.) 166; Truesdail v. Ward, 24 Mich. 134; Smith v. McNeal, 18 P. F. Sm. 164; Browne v. Trustees of Baltimore Church, 37 Maryl. 108, 124. such expenditure would be useless, and do not interpose to prevent the work, he will not be permitted to interrupt the enjoyment of such easement.1 288. In order to an estoppel the representation must be known to be false by the party making it, and it must be believed to be true by the party to whom it was made. If the party against whom an estoppel is alleged does not know the real facts of the case, but speaks and acts under a mistake, he cannot be prejudiced by his action, unless, indeed, his ignorance is due to his own gross negligence. On the other hand, the party alleging the estoppel must not have been acquainted with the facts, otherwise the action of the other party would not mislead him. Of that branch of the above rule which relates to mistake on the part of the person against whom the estoppel is alleged, instances will be found in those cases in which the owners of land have allowed the owners of adjoining lots to build over the boundary line under a mistaken impression in regard to the extent of their own property. Such acquiescence in adverse user, short of the time required by the statute of limitations, will not deprive a party of his rights, because he is under no obligation to assert a title of the existence of which he is igorant. If, however, the mistake is the result of gross negligence, the conduct of the party who thus unintentionally, but negligently, misleads another, may preclude him.3 289. The party setting up the estoppel must actually be deceived by the conduct of the other party. If he acts with a full knowledge of the rights and title of the other party, he cannot complain if that title is subsequently asserted. There can be no fraud when all the parties interested are equally informed of all the facts and mutually assent to them.1 290. The party against whom an estoppel is alleged must Brooks v. Curtis, 4 Lans. (N. Y.) 283; Washburn on Easements, 62, 63. 2 Liverpool Wharf v. Prescott, 7 Allen, 494; 4 Allen, 22; Thayer v. Bacon, 3 Allen, 163; Brewer v. Boston and W. R. Co., 5 Met. 478; Laverty v. Moore, 33 N. Y. 658; Raynor v. Timerson, 51 Barb. 517; Reed v. McCourt, 41 N. Y. 435; Rutherford v. Tracy, 48 Missouri, 325; Kincaid v. Dormey, 51 Id. 552. 3 Slim v. Croucher, 1 De G. F. & J. 518; Calhoun v. Richardson, 30 Conn. 210; Smith v. Newton, 38 Ill. 230; Stone v. Great Western Oil Co., 41 Ill. 85. See, also, Swan v. North British Co., 7 Hurl. & N. 601; 2 Hurl. & C. 175. Rapalee v. Stewart, 27 N. Y. 310; Bales v. Perry, 51 Missouri, 449. intend that his conduct should be acted upon, although he may not have intended to deceive.1 If there is no intention that the conduct should be an inducement to the action of others, there can be no estoppel by such conduct. On the other hand, if there is an intention that the representation shall be relied upon by the other party, there will be an estoppel, although the representation may have been innocently made, and without an intention to deceive.3 The only exceptions to the rule as above stated appear to be the cases of Cornish v. Abington and Manufacturers' Bank v. Hazard;5 in which it was held that parties were estopped who had no intention whatever that their action should be relied upon by others. But these cases seem referable to the ground of negligence. 291. It is essential to an estoppel that it should be acted upon; that is to say, the conduct which is alleged to have produced an estoppel, must actually have been the inducing cause for the action of the party who seeks to set it up. This is illustrated by cases of dedication. If a man dedicates real estate to public use it is with the understanding that such dedication shall be accepted and acted upon by the public. If the public fail to act upon the dedication there can be no estoppel. If no such action has taken place, it will be considered that the offer of dedication has not been accepted, and that, therefore, no estoppel has ensued.7 Many other instances, also, may be found in the books which. are illustrative of the same principle, viz., that an estoppel must be acted upon, or, in other words, that the party setting up the estoppel must have sustained actual damage. 1 Freeman v. Cooke, 2 Exch. 653; In re Bahia and San Francisco R. R. Co., L. R. 3 Q. B. 584. 2 Holdane v. Cold Spring 21 N. Y. 474; Mayenborg v. Haynes, 50 N. Y. 675; Kuhl v. Mayor of Jersey City, 8 C. E. Green, 84. In re Bahia and San Francisco R. R. Co, L. R. 3 Q. B. 584; The Continental Nat. Bank v. The Nat. Bank of the Commonwealth, 50 N. Y. 575. 4 4 Hurl. & N. 549. 8 6 State v. Laies, 52 Missouri, 396; Van Deusen v. Sweet, 51 N. Y. 478. 7 Baker v. Johnston, 21 Mich. 319; Hayne v. West Hoboken,8 C. E. Green, 354. 8 Howard v. Hudson, 2 El. & B. 1; Stimson v. Farnham, L. R. 7 Q. B. 175; Hill v. Epley, 7 Casey, 334; Railroad Co v. Dubois, 12 Wal. 47. See, also, Barker v. Binninger, 14 N. Y. 270; Malloney v. Horan, 49 Id. 111; Rivard v. Gardiner, 39 Ill. 125; Schmaltz v. Avery, 16 Q. B. 655; Helme v. Philadelphia 5 30 N. Y. 226; Bigelow on Estoppel, Life Ins. Co., 11 P. F. Sm. 107. 556, 557. 292. It is important to consider to what extent, against whom, and in whose favor an estoppel may operate. It is a sound and just rule that the estoppel will be limited to the representation made. Thus where a sheriff had a writ against A., but took B. into custody upon the false representation by B. that she was the party named in the writ, but detained her in custody after notice that she was not the party intended, it was held, that, although B. might be estopped from recovering damages for a false arrest, she would not be estopped from an action for the subsequent detention. The estoppel could not operate to justify the detention, for after notice that B. was not the real party the sheriff was no longer deceived by the representation.1 293. It is sometimes difficult to determine whether estoppel by conduct will operate against married women and infants; and the cases on this subject are to a certain extent conflicting.2 The true rule seems to be this: The contract of a person under disability cannot be made good by estoppel. Thus, if a married woman entered into an agreement (which, being made by a married woman, is void) for the sale of real estate, the circumstance that the purchaser went into possession under the contract, and made valuable improvements with the consent and encouragement of the feme, would not operate to estop the latter, because, as no remedy could possibly be had upon the void contract, it would be against the policy of the law to allow the same result to be reached through the indirect medium of an estoppel. Nor would the case of the purchaser be made any better if the woman had represented herself to be sole. Such a representation could amount to no more than a covenant that she was sole, and her coverture would render such a covenant, as well as all others, void.1 But while an estoppel could not have the effect of rendering a married woman's contract valid, it might, nevertheless, in the Dunston v. Paterson, 2 C. B. N. S. 495; Tilton v. Nelson, 27 Barb. 595; Bigelow on Estoppel, 496. 2 Bigelow on Estoppel, 485. 3 Drury v. Foster, 2 Wal. 24; Lowell v. Daniels, 2 Gray, 161; Glidden v. Strupler, 2 P. F. Sm. 400; Morrison v. Wilson, 13 Cal. 494; Rangeley v. Spring, 21 Maine, 130; Concord Bank v. Bellis, 10 Cush. 276; Miles v. Lingerman, 24 Ind. 385. 422. Liverpool Asstn. v. Fairhurst, 9 Ex. |