This work may be done by any party in interest, whether such party have a legal or equitable claim; Jupiter Min. Co. v. Min. Co., 11 Fed. 680. The amount of work re quired by the statute cannot be decreased by any state law or miners' regulation ; Sweet v. Webber, 7 Colo. 443, 4 Pac. 752; Original Co. of Williams & Kellinger v. Min. Co., 60 Cal. 631; and may be done at any time with in the year ; Belk v. Meagher, 104 U. S. 279, 26 L. Ed. 735 ; McGinnis v. Egbert, 8 Colo. 41, 5 Pac. 652.
Failure to perform the work will be ex cused if brought about by actual existing fear of bodily harm, or prevented by coercion or duress actually and presently existing; Slavonian Min. Co. v. Perasich, 7 Fed. 331; Erhardt v. Boaro, 113 U. S. 527, 5 Sup. Ct. 560, 28 L. Ed. 1113.
Where claims are held in common, this annual work may be done on any one claim; R. S. § 2324 ; Chambers v. Harrington, 111 U. S. 350, 4 Sup. Ct. 428, 28 L. Ed. 452.
The apex rule. Ordinarily the locator would be confined to the limits of his sur face measurements both as to surface pos session and beneath it, but by the apex rule the locator is entitled not only to the sur face included within the lines of his loca tion, but also to all of the veins, lodes, and ledges throughout their entire depth, the apex of which lies inside of such surface lines extending downward vertically, albeit such veins, lodes, or ledges may depart from a perpendicular course in such wise as to extend outside of the side lines of the loca tion, provided such right shall not extend beyond the entire lines of the location pro jecting in their own line or until they inter sect the veins or ledges ; R. S. § 2322; Jupi
ter Min. Co. v. Min. Co., 11 Fed. 670 ; Gilpin v. Min. Co., 2 Idaho (Hash.) 696, 23 Pac. 547, 1014; Montana Co. v. Clark, 42 Fed. 626. But this right does not carry with it power to follow into the lands of an adjoining pro prietor holding title to agricultural lands ; Amador Medean Gold Min. Co. v. MM. Co., 36 Fed. 668. But see Cheesman v. Hart, 42 Fed. 98. This rule of the apex has been a fruitful source of litigation, the following being a few of the more important cases: Iron Silver Min. Co. v. Smelting Co., 118 U. S. 196, 6 Sup. Ct. 1177, 30 L. Ed. 98 ; Champion Min. Co. v. Min. Co., 75 Cal. 78, 16 Pac. 513 ; Iron Silver Min. Co. v. Murphy, 3 Fed. 368; Van Zandt v. Min. Co., 8 Fed. 725 ; Iron Silver Min. Co. v. Cheesman, 8 Fed. 297 ; Cheesman v. Hart, 42 Fed. 98 ; Iron Silver Min. Co. v. Murphy, 2 McCrary 121, 3 Fed. 368; Richmond Min. Co. v. Rose, 114 U. S. 576, 5 Sup. Ct. 1055, 29 L. Ed. 273; Flagstaff Silver Min. Co. v. Tarbet, 98 U. S. 463, 25 L. Ed. 253; Cheesman v. Hart, 42 Fed. 98; Iron Silver Min. Co. v. Cheesman, 8 Fed. 297; Tombstone Mill. & Min. Co. v. Mining Co., 1 Ariz. 426, 25 Pac. 794 ; Mc Cormick v. Varnes, 2 Utah 355.