¶1The opinion of the court was delivered by
¶2It is elemental law that a personal judgment rendered against a defendant who has not been served with summons and has no notice of the pendency of the action is void. As to the fact of service, the general rule is that as between the parties to an action the return of the sheriff is conclusive; but if his return is of a fact not within his personal knowledge but dependent upon information received from others a party is not precluded from an inquiry into the facts on which jurisdiction depends. Such inquiry was made *539in this case. - Evidence was offered to the jury and they found that the return of service was not true. ■ The •court approved the finding, it was supported by ample evidence, and we are bound thereby. The judgment of ■the justice of the peace was therefore void. (Bond v. Wilson, 8 Kan. 228.)
¶3The execution sale, made under the void judgment, was equally void and conveyed no title to the pur'chaser. (Case v. Hannahs, 2 Kan. 490; Mastin v. Gray, 19 Kan. 458; 12 Encyc. Pl. & Pr. 12, 90.)
¶4The only remaining question is whether the plaintiff 'was estopped, by his failure to attend the sale and to warn intending purchasers of the invalidity of the .judgment and execution, from prosecuting his claim •against Schott for the value of the wool.
“To constitute an estoppel, the following elements •are essential: (1) There must be conduct, acts, language or silence amounting to a representation or a con•cealment of material facts. (2) These facts must be "known to the party estopped at the time of his said conduct, or, at least, the circumstances must be such that knowledge of them is necessarily imputed to him. (3) The truth concerning these facts must be unknown to 'the other party, claiming the benefit of the estoppel, at 'the time when such conduct was done, and at the time when it was acted upon by him. (4) The conduct must "be done with the intention, or, at least, with the expectation, that it will be acted upon by the other party, or under such circumstances that it is both natural and "probable that it will be so acted upon. (5) The conduct "must be relied upon by the other party, and, thus relying, he must be led to act upon it. (6) He must in fact act upon it in such a manner as to change his position Tor the worse.” (3 Words & Ph. Jud. Def. 2498, and ¡authorities there cited.)
¶5(See, also, Ergenbright v. Henderson, 72 Kan. 29.)
¶6It is true a person in a position and under obligations to speak may be estopped by his silence if he does :not speak. For instance, if one stands by and sees his .property sold as the property of another, the purchaser *540may rely upon his silence, and he may -be estopped thereafter from asserting his ownership.
¶7The plaintiff could have been present at this sale, but was not. He went instead to the justice of the peace who rendered the judgment and issued the execution, probably in the belief that the justice had authority to and would stop the sale. He had no power himself to stop the sale, and he owed no duty to Schott or to any other purchaser in the premises. It would be carrying-the principle of estoppel entirely too far to say that the, plaintiff was estopped by reason of his failure to attend, the sale, especially when it appears that he was pursuing another course which presumably appeared to. him more proper and more likely to accomplish the result of stopping the sale.
¶8The judgment is affirmed.