Soon, however, appeared the battle planes of the ants; but they were surprised and bewildered at the new aerial tactics of their enemies. They had fought against bees before; but never before against bees manned with sharpshooters. And so, although the advance of the striped fleet was stayed and many bees were shot down, an equal number of planes fell victims of the encounter. By night the Cupians had consolidated their position to the south of Lake Luno, and Cabot had established his headquarters in the ruins of Luno Castle. That evening, at a conference with his generals, it was decided that it would not do for the advance to continue too precipitately. In the first place, the air force ought not to be permitted to get too far ahead of the infantry. And in the second place, the casualties among the bees had been altogether too high. Planes could be rebuilt by the Formians, but bees could not be bred to order for Cupia. This was something which Cabot had not figured on. So, now that the first shock attack was over, the advance progressed more slowly in the days that followed, strategy taking the place of brute force. Captured airplanes were repaired and manned by ex-flyers of the old Cupian air navy, and were used whenever possible in place of the bees, but still the mortality of these winged allies continued, until it became evident that, unless something were speedily done, the ant-men would soon regain control of the air. But what was to be done? One day an aviator from a distant point on the front landed at headquarters with a message. As he stood talking to Myles Cabot, he suddenly remarked: “Why, I left my engine running. How careless of me!” And he looked intently at his plane for a moment, whereat the motor ceased its purring. “How did that happen?” Cabot exclaimed. “Does your engine stop whenever you want it to?” “I merely spoke to it, and it obeyed me,” answered the Cupian, simply, yet with suppressed pride. “There are several of us in the air service who have learned that trick.” “What do you mean? How can mere words stop an alcohol motor?” “Oh, it isn’t _words_ that do it,” the airman explained, “but rather a sort of radiation akin to speech. The right kind of an emanation from our antennae will effectively interfere with the ignition at a distance of as much as one parastad.” “And can the same principle be invoked against a kerkool?” “Of course not,” laughed the aviator, “for kerkools employ trophil engines, which ignite by compression, rather than by electricity.” “So they do,” said Cabot. “That is what we call a ‘diesel’ engine on Minos.” And then there was born in the mind of the radio man, the germ of a great idea. He hurriedly sent for Toron, ablest electrician of the whole planet, and for Oya Buh, who had been professor of electricity at the University of Kuana before the civil war. * * * * *