occupancy ls a mode of acquiring property- by which a thing which belongs to nobody becomes the property of the person who took possession of it, with the intention of acquiring a right of owner-ship in it. Civ. Code La. art. 3412; God-dard v. winchell, 86 Iowa, 71, 52 N. W. 1124, 17 L R. A. 788, 41 Am. St Rep. 481