_115 South St. Asaph Street_, Alexandria, is a two-and-one-half-story brick structure over an English basement built about 1800, and still standing. A sign on the structure says "Home of Thomas Mason, circa 1775." It was purchased by Mason in May of 1832, at about the same time that he purchased the lot next door at 117 S. St. Asaph Street. A three-story structure of the last quarter of the nineteenth century now stands there. Mason may have been a tenant at 115 before his purchase, but was already out of the house by November 8, 1833, when a Dr. Wheelwright announced that he had "... removed to the house on St. Asaph Street ... formerly occupied by Thomson F. Mason, Esq." (Deering Davis, Stephen P. Dorsey & Ralph Cole Hall, _Alexandria Houses_, Cornwall, N.Y., Architectural Book Publishing Co., Inc., 1946, p. 126; _Alexandria Gazette_, November 8, 1833. Alexandria Deed Books: U-2, p. 27 (1832); U-2, p. 29 (1832); and M-3, p. 646 (1852).) This list includes only part of the real estate owned by Thomson Francis Mason. He lived in the Cameron Street house during the 1820's. He may have lived in either the Oronoco Street or St. Asaph Street houses before he purchased them. At any rate, he purchased Colross, Hallowell School and the St. Asaph Street houses in the decade before his death. He died in 1838 and was buried at Colross. There are long periods of time unaccounted for and probably many real estate transactions which have not yet been documented. Other Mason Houses _Analostan_, home of General John Mason. Located on the Potomac River in the District of Columbia on Theodore Roosevelt Island, known in the past as Barbadoes, Mason's Island, or Analostan. Built in the 1790's, its design is attributed to George Hadfield. General Mason sold the house about 1833 and moved to Clermont. Parts of the Analostan house stood until the 1930's when they were demolished by the Theodore Roosevelt Memorial Association. (_Sunday Star_, Feb. 6, 1921, Rambler "... History of Analostan Island;" _Star_, June 4, 1958, Rambler, "Revisits Analostan Island;" _Virginia Record_, July 1956, p. 9, Mollie Somerville, "George Mason's Island;" Rowland, _George Mason_, New York, Russell & Russell, 1892 and 1946, Vol I, p. 117; Harry F. Cunningham, Joseph A. Younger, and J. Wilmer Smith, _Measured Drawings of Georgian Architecture in the District of Columbia_, 1750-1820, New York, Architectural Book Company 1914, Sheets 58-61.) _Clermont_, which was purchased by General John Mason and to which he and his family moved in 1833. Site near Fairfax County-Alexandria line, off Clermont Drive, near point where the Richmond, Fredericksburg & Potomac tracks cross Cameron Run. It was demolished in the 19th Century. ("Diary of Miss Mason," beginning Sept. 20th 1833, property of Mrs. Augustus Thorndike, partial copy in Gunston Hall archives (Analostan file); Christine Gibson unpublished report, Fairfax County Public Library, Virginiana Collection.)