"Boche 'plane up to mischief, sir," reported the man by means of the voice-tube. "Steamer getting it hot, I fancy."
Without hesitation Daventry dived steeply, the men standing to their machine-guns and bomb-dropping gear. By the aid of glasses the speck, which was momentarily increasing in size, resolved itself into a large tramp steamer. She had just starboarded her helm in order to maintain a zigzag course, while clouds of smoke pouring from her funnels indicated that the engineers and stokehold staffs were hard at work in their efforts to shake off pursuit.
[Illustration: GV 7 TO THE RESCUE!]
"'Tis a Boche 'bus!" exclaimed the observer, as a circular cloud of white smoke shot up a few feet astern of the tramp. "By Jove, what a beauty!"
Whether the N.C.O. was in earnest, or merely speaking sarcastically of the Hun machine, Daventry could not determine. His attention was centred upon the darting form of a possible antagonist, who, as yet, was ignorant of the British biplane's presence. The Boche machine was remarkable for the unusual appearance of its wings, or rather non-appearance, for they were made of some sort of transparent fabric that rendered them almost invisible. It was only when the aeroplane banked steeply as she hovered over her intended victim that the rays of the setting sun, glinting on the tilted planes, revealed the presence of the V-shaped wings. Even the black cross was absent, as far as the planes were concerned, although they were painted on the top and sides of the fuselage. The elongated body was fancifully decorated in various colours, the whole resembling a freak machine that might, or might not, prove to be a tough customer.
"Wonder if it's Biggs's old pal, Count von Peilfell?" thought Derek. "It's not a seaplane, and the guy is a jolly long way from his base."
A thousand feet—five hundred—three hundred.
"Let him have it," signalled Derek.