The Beacon is an iron basket raised on a post used for signalling in the event of peril or invasion and can be borne in flames or empty. A similar device, used more prosaically as a street light is the cresset. A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Beacon Either device, for reasons that should be quite clear are to be regarded as emblems of “one who is watchful”. The Symbolisms of Heraldry, W. Cecil Wade, George Redway, London, 1898 P116