638.—A general lighthouse authority shall, within their area but subject, in the case of the Commissioners of Northern Lighthouses and the Commissioners of Irish Lights, to the restrictions enacted in this Part of this Act, have the following powers (in this Act referred to as lighthouse powers); namely, powers—

(a) to erect or place any lighthouse, with all requisite works, roads, and appurtenances:

(b) to add to, alter, or remove any lighthouse:

(c) to erect or place any buoy or beacon, or alter or remove any buoy or beacon:

(d) to vary the character of any lighthouse or the mode of exhibiting lights therein.