 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 