 Complete the following phrase:  The next year the Royal Automobile Club took a lease on the airfield and set out a more formal racing circuit. Their first two races were held on the runways themselves, with long straights separated by tight hairpin corners, the track demarcated by hay bales. However, for the 1949 International Trophy meeting, it was decided to switch to the perimeter track. This arrangement was used for the 1950 and 1951 Grands Prix. In 1952 the start line was moved from the Farm Straight to the straight linking Woodcote and Copse corners, and this layout remained largely unaltered for the following 38 years. For the 