The glimpse he had caught of the hostile aeroplane as it flashed by, suggested that it was a much larger and more powerful machine than his own. If this were indeed the case, he was probably quite outmatched in speed as in armament. But he saw in a moment that the possession of the smaller machine might tend to his own advantage, for he could wheel in narrow parts of the valley where the attempt would prove destructive to the enemy. Moreover, he knew the valley thoroughly; the others, though no doubt vastly superior to him in a military sense, lacked local experience and had everything to learn. Time was on his side. As soon as he began his flight he knew that he had gained one point. If the enemy had turned at his customary wheeling-place, their aeroplane would already have been in sight. The next suitable spot was several miles farther up the valley, unless indeed they should rise to a much greater height than that at which they had passed. Such an ascension would consume time; it would further make it very difficult for them to drop their bombs with any degree of accuracy. Whether they rose or continued their flight at the same altitude until they reached the wider turning-place, they would not be back for four or five minutes. Lawrence resolved to utilise this breathing space. He flew on until he reached his usual turning-place, then began to mount in a spiral course. While he was doing this, two considerations flashed through his mind. If, when he met the enemy, he should be still below them, he must fly on in the opposite direction, for the chance of being hit by a bomb, when the machines were passing at the rate of perhaps a hundred and fifty miles an hour, would be very slight. His only fear in that case was that they would fly straight back to the mine and work havoc there without a possibility of interference. If, on the other hand, he were above them, his best course would be to fly in the same direction, and try to drop his bombs on them. When two express trains are running the same way, it is possible, however great their speed, to cast an object from a carriage of one through an open window of the other. He was still ascending when Fazl shouted that the enemy’s aeroplane was in sight, at a greater height. "Rifle!" said Lawrence instantly, as he headed up the valley.