(Saxon beacon), an ancient species of signal, consisting generally of a long pole to which was fastened a pitch-barrel to be fired by night, and to produce smoke by day. These were erected on conspicuous eminences, to give notice of an approaching invasion.

Beacons are also marks and signs erected on the coasts for guiding and preserving vessels at sea by night as well as by day. The erection of beacons, lighthouses, and sea-marks, is a branch of the royal prerogative. The sovereign has the exclusive power, by commission under the great seal, to cause them to be erected in fit and convenient places, as well upon the lands of the subject as upon the demesnes of the crown, which power is usually vested by letters-patent in the office of lord high admiral. By statute 8th Elizabeth, cap. 13, the corporation of the Trinity-house is empowered to set up any beacons or sea-marks wherever they shall think such necessary; and the owner of the land or any other person destroying these, or taking down any steeple, tree, or other known sea-mark, is declared liable to severe penalties.