Perspectives of tower (& gamekeeper's house), 1848, in Victoria & Albert Museum, RIBA Drawings Collection, SD103/2 and PB390/12, see Catalogue of the Drawings Collection of the Royal Institute of British Architects B (RIBA, 1972), 122,124, and British Architectural Library Catalogue, http://riba.sirsidynix.net.uk/uhtbin/cgisirsi/E2iRjM0D2D/MAIN_CAT/200680089/13 (last visited, Apr 2009).; alternative design in collection of Marquess of Dufferin & Ava, see Hugh Dixon, Ulster Architecture 1800-1900 (UAHS, 1972), 12 (no. 21,22); Gavin Stamp, 'Helen's Tower'. in Clandeboye(UAHS., 1985), 2833(illus.)C.E.B. Brett, Buildings of North County Down (UAHS, 2002), 268-9(illus.); Howard Colvin, A Biographical dictionary of British architects 1600-1840 (4th edn., 2008), 194.