In its early years what is now Heathrow Airport was the Great West Aerodrome, sometimes known as Heathrow Aerodrome. Before 1920 About 1410: The first known mention of a semi-rural lane called Heathrow (spelled La Hetherewe). Heathrow divided farmland and heath until 1819 when the heath also became farmland. Specifically, the lane divided the hamlet of Harmondsworth (on the northwestern edge of today's airport) from the 17th and 18th century highwaymen's lair of Hounslow Heath (centered roughly where Terminal 3 is today). A little of Harlington, Hatton in Bedfont and Stanwell also fall within the airport's perimeter road. 1915: Fairey Aviation, founded by British aero-engineer and plane builder Richard Fairey, started assembling and flight testing its aircraft from Northolt Aerodrome, about six miles north of the modern Heathrow airport. 1917-1919: About southeast of Heathrow, Hounslow Heath Aerodrome was the only London aerodrome with customs facilities in 1919. After the closure of Hounslow Heath Aerodrome in 1919, Croydon Airport became the principal London Airport. 1920s 1925: Norman Macmillan, an RAF officer, made a forced landing and take-off at Heathrow. He noted the flatness of the land and its suitability for an airfield. The land was at the time used for market gardening and wheat growing. 1928: The Air Ministry gave Fairey notice to cease using Northolt. Fairey Aviation needed an airfield for flight testing of aircraft designed and manufactured at its factory in North Hyde Road, Hayes. Norman Macmillan, by then Fairey's chief test pilot, remembered the forced landing and take-off at Heathrow in 1925, and recommended the suitability of the area for an aerodrome. Macmillan flew aerial surveys of the site. 1929: Fairey Aviation started by buying of farmland in four adjoining plots near southeast of the hamlet of Heathrow from four local landowners, for about £1,500, at the typical 1929 market rate of £10 per acre. (The first plot bought was 71 acres from the Rev. R. Ross, vicar of Harmondsworth.) The site was bounded to the northeast by Cain's Lane, to the south by the Duke of Northumberland's River, and to the west by High Tree Lane. The airfield boundaries were south of the Bath Road, northwest of the Great South West Road, and about two miles west of the western end of the Great West Road. The airfield was about three miles by road from the Hayes factory. 1930s June 1930: The airfield was declared operational. 1930