In the opposite direction to the archway of exit, the slight, active figure in the perfectly-cut blue serge morning clothes and pot hat of Bond Street block, was rapidly walking. Bawne doubted his eyes for a moment before he remembered that the Collingwood Avenue ran along that side of the Flying Ground fence. There was a smaller gate in charge of a commissionaire, in the fence, about a hundred yards along it. Taxi-cabs were standing outside the gate. Any person on foot or awheel, leaving the Flying Ground, must pass the gate and the taxi-stand. You could see through the chinks in the fence when they passed, nip out when they were well by, and follow in a green-flagged chuffer. Bawne had settled this to his satisfaction before a wrench at the rein of duty pulled his head round to the business on hand. "I’m not spying on Mr. Sherbrand," the boy told himself, gritting his small square teeth doggedly. "I’ve _got_ to listen, so as to understand the German’s game. And I’m going to. This is how I’m going to!" He began to turn hand-springs after the fashion of the London street Arab, thus lessening the distance between himself and the talking men. They glanced at him, and Sherbrand grinned, but they looked back again directly at each other. Then Bawne threw himself down and panted, rolled over and lay, still panting. Now he was near enough to hear what passed between the two. Sherbrand said: "No, I was not particularly solid in my conviction that the aërial stabiliser would take the fancy of the Chiefs of the Service Aëronautique. An accident prevented me from witnessing the final test, and I got what the Americans call cold feet and judged it no use staying in France longer. So I flew back here, starting early by daylight the next morning, with Davis, my mechanic, and found a cable waiting at my office to say the working of the invention had been observed with interest by the Chiefs of the S. Aë. F., and that if I could carry out a satisfactory time-trial at my headquarters in the presence of the French Consul, the authorities at the Ministry of War would be willing to buy my patents for France. As it happened, I was suffering from a slight obstruction in the nasal passages, that spoiled my climbing. It was absolutely necessary to go into Hospital. That is why I could not give M. Jourdain an earlier date for the hovering-test you have just seen carried out." Von Herrnung demanded: "But did you not receive a letter containing a business proposal? A communication from Rathenau, Wolff and Brothers, Aëromotor Engineers of Paris, 200, Rue Gagnette? I happen to know that it was posted, and the date being that of the Paris trial, Herren Rathenau and Wolff certainly possess the prior claim!" "Their communication reached me in Hospital, three days later than the French War Office cable," Sherbrand answered. "It had been forwarded from the makeshift hangar I rented at Drancy—a mistake in the address being the reason of the delay!"