"There's a lot to be worked out in this thing, yet, though," declared Ben, "and if you're right about the Lassans making a comeback, precious little time in which to work it out. For one thing, we've got to get a searchlight that will throw a narrow pencil of light for a long distance. I don't think those elephant-men are going to let us poke this thing under their noses. And for another we've got to dope out something to keep it in and some way to furnish current for it...." "Can't you work it from a tank?" asked Murray, "and rig up a friction accumulator to work from the tracks?" "I can, but I don't like the idea," Sherman replied. "From the way those Lassans took to our airplanes, I could make a guess that when they come, they're going to come in some kind of flying machine. The dodos are no good in modern war. We'd never catch any kind of an airplane with a tank." "How about an airplane for yourselves?" "Too unsteady and too frail. I want something that will take a few pokes and not fold up." "Say, you guys have less ingenuity for a couple of inventors than anyone I ever heard of," Gloria put in. "Why don't you get one of these Australian rocket-planes and fix it up. It's big enough to hold all your foolishness, and if this thing is half as powerful as it looks, you ought to be able to harness it some way for a power-plant. Then you can plaster your rocket all over with armor. I think--" Sherman interrupted her by bringing his fist down on the table with a bang that made the glasses rattle. "You've got it! By the nine gods of Clusium! With the punch this thing gives us used as a rocket, we'd have power enough to fly to the moon if we wanted to. Why a rocket airplane at all? Why not a pure rocket? Let's go." It was another week before workmen, even toiling with all the machine-shop facilities of Philadelphia at their disposal, and working day and night, could turn out the machine to Sherman's design, and it was two more before the apparatus was installed. The trial trip was set for the early morning when there would be least chance of atmospheric disturbance. The _Monitor_ (she had been named for the famous fighting craft with which the American navy ushered in a new age in the history of war) now stood near the center of the flying field at the Philadelphia airport--a long, projectile-like vessel with gleaming metal sides, set with heavy windows, ten feet in diameter and nearly twice as long. At her stern a funnel-like opening led to the interior. This was the exhaust for the power-plant. At her bow the sharp nose was blunted off and its tip was occupied by the lens of a high-powered parabolic searchlight, slightly recessed, and with the discharge tubes for the atomic nuclei arranged around its edge so they would be thrown directly into the light-beam as soon as generated.