HOUNSLOW, a town in Middlesex, England, 121 m. W. by S. of St. Paul's Cathedral, London. Pop. (1921) 23,506. It is a residential suburb of London at the junction of two great roads from the west of England and was an important coaching sta tion. A priory of friars of the Holy Trinity was founded at Hounslow in 1296. Hounslow Heath had, according to the sur vey of J.546, an area of 4,293 ac. It was the site of Roman and British camps and a few centuries ago was a resort of highway men. In 1784 the base-line of the first trigonometrical survey in England was laid down on the heath. It began to be enclosed to wards the end of the reign of George III. In Osterley Park, north east of Hounslow, Sir Thomas Gresham built a mansion in and this was rebuilt about 177o. Hounslow is divided between the parishes of Heston and Isleworth. Pop. (1931) of this urban district,