twelve o'clock
`` Hold tight now , Tom ! I 'm going to let her out a bit . '' Swiftly the grey car gathered speed . In a rush of dust , with horn blowing and exhaust sputtering behind them , the car shot over the line , and , just as a whistle boomed out the twelve o'clock dinner signal , Jack was in hostile territory . The war was on ! Behind them there was a confused shouting . The car was built so that it was easy to look behind .