Prejudice resulting to the adversary party or to a third party from lapse of time is an essential element of laches, without which mere delay does not amount to laches.1 If such prejudice results from such unreasonable and unexplained delay, however, laches exists.2 Thus the acquisition by innocent third persons of interests in the property the recovery of which is sought, as by purchase,3 or by taking a mortgage thereon as security for a loan,4 has been held sufficient when coupled with unreasonable delay on the part of the plaintiff to prevent him from obtaining equitable relief. Thus a city in alleged violation of its contract with a water company proceeded to issue bonds and with the proceeds to build its own waterworks, out of the revenues arising from which such bonds were to be paid. Such water company and its bondholders objected orally to such conduct, but took no steps to preserve their rights by litigation until the city had issued bonds and out of the proceeds had constructed a dam across the Colorado River and had laid pipe. It was held that, whatever the original rights of the parties, they had, by their laches, lost the right to equitable relief by injunction against the completion of the waterworks.5 So an action to charge land with an invalid levee assessment, on the theory that the owner was estopped to deny the validity of such assessments, is barred where the property had changed hands repeatedly and the owners had spent large sums for repairing the levee and had become liable for large assessments under a new statute.6 The facts that the plaintiff has waited an unreasonable time, and that the value of the property whose recovery is sought has advanced greatly, will prevent relief from being given.7 Accordingly in property the value of which is fluctuating and speculative8 such as oil9 or mining10 properties, a delay may be unreasonable, though in case of property of more stable value it would not be unreasonable. A delay for so long a time that it has become difficult to procure evidence,11 as of oral offers dealing with technicalities of a manufacture12 may amount to laches. So a delay in enforcing a contract until the adversary party is broken down mentally13 or is dead14 is laches. A delay for an unreasonable time during which the adversary party expends money or labor upon the property in dispute15 is laches. However, allowing the sanitary district of Chicago to construct a drainage canal was held not to be laches.16

1 See Sec. 1706, 1707.

2 O'Brien v. Wheelock, 184 U. S. 450; Penn Mutual Life Ins. Co. v. Austin, 168 U. S. 685; Abraham v. Ordway, 158 U. S. 416; Fisher v. Patterson, 197 111. 414; 64 N. E. 353; affirming 99 111. App. 70; Walker v. Warner, 179 111. 16; 53 N. E. 594; Long v. Olson, 115 la. 388; 88 N. W. 933; Holman v. Winterboer, 107 la. 270; 77 X. W. 1060; Dunbar v. Green, 66 Kan. 557; 72 Pac. 243; Smith v. Carlow, 114 Mich. 67; 72 N. W. 22; Coyne v. Sayre, 54 N. J. Eq. 702; 36 Atl. 96; Burr v. Kase, 168 Pa. St. 81: 31 Atl. 954; Gorham v. Sayles, 23 R. I. 449; 50 Atl. 848; Chase v. Chase. 20 R. I. 202; 37 Atl. 804; Nelson v. Triplett, 162

99 Va. 421; 39 S. E. 150; Shields v. Tarleton, 48 W. Va. 343; 37 S. E. 589.

3 Abraham v. Ordway, 158 U. S. 416 (delay of twenty years) ; Fisher v. Patterson, 197 111. 414; 64 X. E. 353 (delay of two and one-half years after knowledge of facts) ; Gorham v. Sayles, 23 R. I. 449; 50 Atl. 848 (delay of twenty-two years) ; Nelson v. Triplett, 99 Va. 421; 39 S. E. 1.50 (delay of twenty-five years) ; Shields v. Tarleton, 48 W. Va. 343; 37 S. E. 589 (delay of almost twenty-one years).

4 Johnson v. Transit Co., 156 U.-S. 618. (Delay of seven years.)

5 Penn Mutual Life Ins. Co. v. Austin. 16S U. & 685.

6 O'Brien v. Wheelock, 184 U. S. 450.

7 Twin Lick Oil Co. v. Marbury, 91 U. S. 587 (delay of four years) ; Hendry y. Benlisa, 37 Fla. 609; 34 L. R. A. 283; 20 So. 800; Dunbar v. Green, 66 Kan. 557; 72 Pac. 243.

8 Hay ward v. Bank, 96 U. S. 611; Royal Bank v. Depot To., 125 Mass. 490; Melms v. Brewing. Co., 93 Wis. 153; 57 Am. St. Rep. b"9; 46 L. R. A. 478; 66 X. W. 518.

9 Twin Lick Oil Co. /. Marbury, 91 U. S. 587.

10 Crildersleeve v. Mining Co., 161 U. S. 573; Johnston v Mining Co., 148 U. S. 360; Compo v. Iron Co., 50 Mich. 578; 16 X. YV 295; Barnard v. Iron Co., 85 Tenn. 139; 2 S. W. 21.

11 Whitney v. Fox, 166 U. S. 637;

Willard v. Woqd, 164 U. S. 502; Bell v. Hudson, 73 Cal. 285; 2 Am. St. Rep. 791; 14 Pac. 791; Thomas v. Van Meter, 164 111. 304; 45 X. E. 405; Harrod v. Flountleroy, 3 J. J. Mar. (Ky.) 548; Doane v. Preston, 183 Mass. 569; 67 X. E. 867; Wilson v. Wilson, 41 Or. 459; 69 Pac. 923; Bolton v. Dickens. 4 Lea (Tenn.) 569; Cross v. Bowker, 102 Wis. 497; 78 X. W. 564.

12 Doane v. Preston, 183 Mass. 569; 67 N. E. 867.

13 Whitney v. Fox, 166 U. S. 637.

14 Yeamans v. James, 29 Kan. 373; Dismal Swamp Land Co. v. Macauley's Admr., 85 Va. 16; 6 S. E. 697.

15 Long v. Olson, 115 la. 388; 88 N. W. 933.

16 Missouri v. Illinois, 180 U. S 208.