Every railroad corporation is granted the right of way for the location, construction, and maintenance of its necessary works, and for every necessary adjunct thereto, over any swamp, overflowed, or other public lands of the State not otherwise disposed of or in use, not in any case exceeding in length or width that which is necessary for the construction of such works and adjuncts, or for the protection thereof, and in no case to exceed 200 feet in width.
These grants do not apply to public lands of the State within the corporate limits of cities, or within three miles thereof.