Crane spoke briefly in reply and the little group of Earthly wanderers stepped into the elevator. As they sped upward toward the control room, door after door shot into place behind them, establishing a manifold seal. Seaton's hand played over the controls and the great cruiser of the void tilted slowly upward until its narrow prow pointed almost directly into the zenith. Then, very slowly at first, the unimaginable mass of the vessel floated lightly upward, with a slowly increasing velocity. Faster and faster she flew—out beyond measurable atmosphere, out beyond the outermost limits of the green system. Finally, in interstellar space, Seaton threw out super-powered detector and repelling screens, anchored himself at the driving console with a force, set the power control at "molecular" so that the propulsive force affected alike every molecule of the vessel and its contents, and, all sense of weight and acceleration lost, he threw in the plunger switch which released every iota of the theoretically possible power of the driving mass of uranium.

Staring intently into the visiplate, he corrected their course from time to time by minute fractions of a second of arc; then, satisfied at last, he set the automatic forces which would guide them, temporarily out of their course, around any obstacles, such as the uncounted thousands of solar systems lying in or near their path. He then removed the restraining forces from his body and legs, and with a small pencil of force wafted himself over to Crane and the two women.

"Well, bunch," he stated, matter-of-fact, "we're on our way. We'll be this way for some time, so we might as well get used to it. Any little thing you want to talk over?"

"How long will it take us to catch 'em?" asked Dorothy "Traveling this way isn't half as much fun as it is when you let us have some weight to hold us down."

"Hard to tell exactly, Dottie. If we had precisely four times their acceleration and had started from the same place, we would of course overtake them in just the number of days they had the start of us, since the distance covered at any constant positive acceleration is proportional to the square of the time elapsed. However, there are several complicating factors in the actual situation. We started out not only twenty-nine days behind them, but also a matter of five hundred thousand light-years of distance. It will take us quite a while to get to their starting-point. I can't tell even that very close, as we will probably have to reduce this acceleration before we get out of the Galaxy, in order to give detectors and repellers time to act on stars and other loose impediments. Powerful as those screens are and fast as they work, there is a limit to the velocity we can use here in this crowded Galaxy. Outside it, in free space, of course we can open her up again. Then, too, our acceleration is not exactly four times theirs, only three point nine one eight six. On the other hand, we don't have to catch them to go to work on them. We can operate very nicely at five thousand light-centuries. So there you are—it'll probably be somewhere between thirty-nine and forty-one days, but it may be a day or so more or less."

"How do you know they are using copper?" asked Margaret. "Maybe their scientists stored up some uranium and know how to use it."

"Nope, that's out like a light. First, Mart and I saw only copper bars in their ship. Second, copper is the most efficient metal found in quantity upon their planet. Third, even if they had uranium or any metal of its class, they couldn't use it without a complete knowledge of, and ability to handle, the fourth and fifth orders of rays."

"It is your opinion, then, that destroying this last Fenachrone vessel is to prove as simple a matter as did the destruction of the others?" Crane queried, pointedly.

"Hm-m-m. Never thought about it from that angle at all, Mart.... You're still the ground-and-lofty thinker of the outfit, ain't you? Now that you mention it, though, we may find that the Last of the Mohicans ain't entirely toothless, at that. But say, Mart, how come I'm as wild and cock-eyed as I ever was? Rovol's a slow and thoughtful old codger, and with his accumulation of knowledge it looks like I'd be the same way."

"Far from it," Crane replied. "Your nature and mine remain unchanged. Temperament is a basic trait of heredity, and is neither affected nor acquired by increase of knowledge. You acquired knowledge from Rovol, Drasnik, and others, as did I—but you are still the flashing genius and I am still your balance wheel. As for Fenachrone toothlessness: now that you have considered it, what is your opinion?"

"Hard to say. They didn't know how to control the fifth order rays, or they wouldn't have run. They've got real brains, though, and they'll have something like seventy days to work on the problem. While it doesn't stand to reason that they could find out much in seventy days, still they may have had a set-up of instruments on their detectors that would have enabled them to analyze our fields and thus compute the structure of the secondary projector we used there. If so, it wouldn't take them long to find out enough to give us plenty of grief—but I don't really believe that they knew enough. I don't quite know what to think. They may be easy and they may not; but, easy or hard to get, we're loaded for bear and I'm plenty sure that we'll pull their corks."

"So am I, really, but we must consider every contingency. We know that they had at least a detector of fifth-order rays...."

"And if they did have an analytical detector," Seaton interrupted, "they'll probably slap a ray on us as soon as we stick our nose out of the Galaxy!"

"They may—and even though I do not believe that there is any probability of them actually doing it, it will be well to be armed against the possibility."

"Right, old top—we'll do that little thing!"

* * * * *

Uneventful days passed, and true to Seaton's calculations, the awful acceleration with which they had started out could not be maintained. A few days before the edge of the Galaxy was reached, it became necessary to cut off the molecular drive, and to proceed with an acceleration equal only to that of gravitation at the surface of the Earth. Tired of weightlessness and its attendant discomforts to everyday life, the travelers enjoyed the interlude immensely, but it was all too short—too soon the stars thinned out ahead of "Three's" needle prow. As soon as the way ahead of them was clear, Seaton again put on the maximum power of his terrific bars and, held securely at the console, set up a long and involved integral. Ready to transfer the blended and assembled forces to a plunger, he stayed his hand, thought a moment, and turned to Crane.

"Want some advice, Mart. I'd thought of setting up three or four courses of five-ply screen on the board—a detector screen on the outside of each course, next to it a repeller, then a full-coverage ether-ray screen, then a zone of force, and a full-coverage fifth-order ray-screen as a liner. Then, with them all set up on the board, but not out, throw out a wide detector. That detector would react upon the board at impact with anything hostile, and automatically throw out the courses it found necessary."

"That sounds like ample protection, but I am not enough of a ray-specialist to pass an opinion. Upon what point are you doubtful?"

"About leaving them on the board. The only trouble is that the reaction isn't absolutely instantaneous. Even fifth-order rays would require a millionth of a second or so to set the courses. Now if they were using ether waves, that would be lots of time to block them, but if they should happen to have fifth-order stuff it'd get here the same time our own detector-impulse would, and it's just barely conceivable that they might give us a nasty jolt before the defenses went out. Nope, I'm developing a cautious streak myself now, when I take time to do it. We've got lots of uranium, and I'm going to put one course out."

"You cannot put everything out, can you?"

"Not quite, but pretty nearly, I'll leave a hole in the ether screen to pass visible light—no, I won't either. You folks can see just as well, even on the direct-vision wall plates, with light heterodyned on the fifth, so we'll close all ether bands, absolutely. All we'll have to leave open will be the one extremely narrow band upon which our projector is operating, and I'll protect that with a detector screen. Also, I'm going to send out all four courses, instead of only one—then I'll know we're all right."

"Suppose they find our one band, narrow as it is? Of course, if that were shut off automatically by the detector, we'd be safe; but would we not be out of control?"

"Not necessarily—I see you didn't get quite all this stuff over the educator. The other projector worked that way, on one fixed band out of the nine thousand odd possible. But this one is an ultra-projector, an improvement invented at the last minute. Its carrier wave can be shifted at will from one band of the fifth order to any other one; and I'll bet a hat that's one thing the Fenachrone haven't got! Any other suggestions?... all right, let's get busy!"

A single light, quick-acting detector was sent out ahead of four courses of five-ply screen, then Seaton's fingers again played over the keys, fabricating a detector screen so tenuous that it would react to nothing weaker than a copper power bar in full operation and with so nearly absolute zero resistance that it could be driven at the full velocity of his ultra-projector. Then, while Crane watched the instruments closely and while Dorothy and Margaret watched the faces of their husbands with only mild interest, Seaton drove home the plunger that sent that prodigious and ever-widening fan ahead of them with a velocity unthinkable millions of times that of light. For five minutes, until that far-flung screen had gone as far as it could be thrown by the utmost power of the uranium bar, the two men stared at the unresponsive instruments, then Seaton shrugged his shoulders.

"I had a hunch," he remarked with a grin. "They didn't wait for us a second. 'I don't care for some,' says they, 'I've already had any.' They're running in a straight line, with full power on, and don't intend to stop or slow down."

"How do you know?" asked Dorothy. "By the distance? How far away are they?"

"I know, Red-Top, by what I didn't find out with that screen I just put out. It didn't reach them, and it went so far that the distance is absolutely meaningless, even expressed in parsecs. Well, a stern chase is proverbially a long chase, and I guess this one isn't going to be any exception."

* * * * *

Every eight hours Seaton launched his all-embracing ultra-detector, but day after day passed and the instruments remained motionless after each cast of that gigantic net. For several days the Galaxy behind them had been dwindling from a mass of stars down to a huge bright lens; down to a small, faint lens; down to a faintly luminous patch. At the previous cast of the detector it had still been visible as a barely-perceptible point of light in the highest telescopic power of the visiplate. Now, as Dorothy and Seaton, alone in the control room, stared into that visiplate, everything was blank and black; sheer, indescribable blackness; the utter and absolute absence of everything visible or tangible.

"This is awful, Dick.... It's just too darn horrible. It simply scares me pea-green!" she shuddered as she drew herself to him, and he swept both his mighty arms around her in a soul-satisfying embrace.

"'Sall right, darling. That stuff out there'd scare anybody—I'm scared purple myself. It isn't in any finite mind to understand anything infinite or absolute. There's one redeeming feature, though, cuddle-pup—we're together."

"You chirped it, lover!" Dorothy returned his caresses with all her old-time fervor and enthusiasm. "I feel lots better now. If it gets to you that way, too, I know it's perfectly normal—I was beginning to think maybe I was yellow or something ... but maybe you're kidding me?" she held him off at arm's length, looking deep into his eyes: then, reassured, went back-into his arms. "Nope, you feel it, too," and her glorious auburn head found its natural resting-place in the curve of his mighty shoulder.

"Yellow!... You?" Seaton pressed his wife closer still! and laughed aloud. "Maybe—but so is picric acid; so is nitroglycerin; and so is pure gold."

"Flatterer!" Her low, entrancing chuckle bubbled over. "But you know I just revel in it. I'll kiss you for that!"

"It is awfully lonesome out here, without even a star to look at," she went on, after a time, then laughed again. "If the Cranes and Shiro weren't along, we'd be really 'alone at last,' wouldn't we?"

"I'll say we would! But that reminds me of something. According to my figures, we might have been able to detect the Fenachrone on the last test, but we didn't. Think I'll try 'em again before we turn in."

Once more he flung out that tenuous net of force, and as it reached the extreme limit of its travel, the needle of the micro-ammeter flickered slightly, barely moving off its zero mark.

"Whee! Whoopee!" he yelled. "Mart, we're on 'em!"

"Close?" demanded Crane, hurrying into the control room upon his beam.

"Anything but. Barely touched 'em—current something less than a thousandth of a micro-ampere on a million to one step-up. However, it proves our ideas are O. K."

The next day—Skylark III was running on Eastern Standard Time, of the Terrestrial United States of America—the two mathematicians covered sheet after sheet of paper with computations and curves. After checking and rechecking the figures, Seaton shut off the power, released the molecular drive, and applied acceleration of twenty-nine point six oh two feet per second; and five human beings breathed as one a profound sigh of relief as an almost-normal force of gravitation was restored to them.

"Why the let-up?" asked Dorothy. "They're an awful long ways off yet, aren't they? Why not hurry up and catch them?"

"Because we're going infinitely faster than they are now. If we kept up full acceleration, we'd pass them so fast that we couldn't fight them at all. This way, we'll still be going a lot faster than they are when we get close to them, but not enough faster to keep us from maneuvering relatively to their vessel, if things should go that far. Guess I'll take another reading on 'em."

"I do not believe that I should," Crane suggested, thoughtfully. "After all, they may have perfected their instruments, and yet may not have detected that extremely light touch of our ray last night. If so, why put them on guard?"

"They're probably on guard, all right, without having to be put there—but it's a sound idea, anyway. Along the same line I'll release the fifth-order screens, with the fastest possible detector on guard. We're just about within reach of a light copper-driven ray right now, but it's a cinch they can't send anything heavy this far, and if they think we're overconfident, so much the better."

"There," he continued, after a few minutes at the keyboard. "All set. If they put a detector on us, I've got a force set to make a noise like a New York City fire siren. If pressed, I'd reluctantly admit that in my opinion we're carrying caution to a point ten thousand degrees below the absolute zero of sanity. I'll bet my shirt that we don't hear a yip out of them before we touch 'em off. Furthermore...."

* * * * *

The rest of his sentence was lost in a crescendo bellow of sound. Seaton, still at the controls, shut off the noise, studied his meters carefully, and turned around to Crane with a grin.

"You win the shirt, Mart. I'll give it to you next Wednesday, when my other one comes back from the laundry. It's a fifth-order detector ray, coming in beautifully on band forty-seven fifty, right in the middle of the order."

"Aren't you going to put a ray on 'em?" asked Dorothy in surprise.

"Nope—what's the use? I can read theirs as well as I could one of my own. Maybe they know that too—if they don't we'll let 'em think we're coming along, as innocent as Mary's little lamb, so I'll let their ray stay on us. It's too thin to carry anything, and if they thicken it up much I've got an axe set to chop it off." Seaton whistled a merry lilting refrain as his fingers played over the stops and keys.

"Why, Dick, you seem actually pleased about it." Margaret was plainly ill at ease.

"Sure am. I never did like to drown baby kittens, and it kinda goes against the grain to stab a guy in the back, when he ain't even looking, even if he is a Fenachrone. If they can fight back some I'll get mad enough to blow 'em up happy."

"But suppose they fight back too hard?"

"They can't—the worst that can possibly happen is that we can't lick them. They certainly can't lick us, because we can outrun 'em. If we can't get 'em alone, we'll beat it back to Norlamin and bring up re-enforcements."

"I am not so sure," Crane spoke slowly. "There is, I believe, a theoretical possibility that sixth-order rays exist. Would an extension of the methods of detection of fifth-order rays reveal them?"

"Sixth? Sweet spirits of niter! Nobody knows anything about them. However, I've had one surprise already, so maybe your suggestion isn't as crazy as it sounds. We've got three or four days yet before either side can send anything except on the sixth, so I'll find out what I can do."

He flew at the task, and for the next three days could hardly be torn from it for rest; but

"O. K., Mart," he finally announced. "They exist, all right, and I can detect 'em. Look here," and he pointed to a tiny receiver, upon which a small lamp flared in brilliant scarlet light.

"Are they sending them?"

"No, fortunately. They're coming from our bar. See, it shines blue when I put a grounded shield between it and the bar, and stays blue when I attach it to their detector ray."

"Can you direct them?"

"Not a chance in the world. That means a lifetime, probably many lifetimes, of research, unless somebody uses a fairly complete pattern of them close enough to this detector so that I can analyze it. 'Sa good deal like calculus in that respect. It took thousands of years to get it in the first place, but it's easy when somebody that already knows it shows you how it goes."

"The Fenachrone learned to direct fifth-order rays so quickly, then, by an analysis of our fifth-order projector there?"

"Our secondary projector, yes. They must have had some neutronium in stock, too—but it would have been funny if they hadn't, at that—they've had intra-atomic power for ages."

Silent and grim, he seated himself at the console, and for an hour he wove an intricate pattern of forces upon the inexhaustible supply of keys afforded by the ultra-projector before he once touched a plunger.

"What are you doing? I followed you for a few hundred steps, but could go no farther."

"Merely a little safety-first stuff. In case they should send any real pattern of sixth-order rays this set-up will analyze it, record the complete analysis, throw out a screen against every frequency of the pattern, throw on the molecular drive, and pull us back toward the galaxy at full acceleration, while switching the frequency of our carrier wave a thousand times a second, to keep them from shooting a hot one through our open band. It'll do it all in about a millionth of a second, too—I want to get us all back alive if possible! Hm—m. They've shut off their ray—they know we've tapped onto it. Well, war's declared now—we'll see what we can see."

Transferring the assembled beam to a plunger, he sent out a secondary projector toward the Fenachrone vessel, as fast as it could be driven, close behind a widespread detector net. He soon found the enemy cruiser, but so immense was the distance that it was impossible to hold the projection anywhere in its neighborhood. They flashed beyond it and through it and upon all sides of it, but the utmost delicacy of the controls would not permit of holding even upon the immense bulk of the vessel, to say nothing of holding upon such a relatively tiny object as the power bar. As they flashed repeatedly through the warship, they saw piecemeal and sketchily her formidable armament and the hundreds of men of her crew, each man at battle station at the controls of some frightful engine of destruction. Suddenly they were cut off as a screen closed behind them—the Earth-men felt an instant of unreasoning terror as it seemed that one-half of their peculiar dual personalities vanished utterly. Seaton laughed.

"That was a funny sensation, wasn't it? It just means that they've climbed a tree and pulled the tree up after them."

"I do not like the odds, Dick," Crane's face was grave. "They have many hundreds of men, all trained; and we are only two. Yes, only one, for I count for nothing at those controls."

"All the better, Mart. This board more than makes up the difference. They've got a lot of stuff, of course, but they haven't got anything like this control system. Their captain's got to issue orders, whereas I've got everything right under my hands. Not so uneven as they think!"

* * * * *

Within battle range at last, Seaton hurled his utmost concentration of direct forces, under the impact of which three courses of Fenachrone defensive screen flared through the ultra-violet and went black. There the massed direct attack was stopped—at what cost the enemy alone knew—and the Fenachrone countered instantly and in a manner totally unexpected. Through the narrow slit in the fifth-order screen through which Seaton was operating, in the bare one-thousandth of a second that it was open, so exactly synchronized and timed that the screens did not even glow as it went through the narrow opening, a gigantic beam of heterodyned force struck full upon the bow of the Skylark, near the sharply-pointed prow, and the stubborn metal instantly flared blinding white and exploded outward in puffs of incandescent gas under the awful power of that Titanic thrust. Through four successive skins of inoson, the theoretical ultimate of possible strength, toughness, and resistance, that frightful beam drove before the automatically-reacting detector closed the slit and the impregnable defensive screens, driven by their mighty uranium bars, flared into incandescent defense. Driven as they were, they held, and the Fenachrone, finding that particular attack useless, shut off their power.

"Wow! They sure have got something!" Seaton exclaimed in unfeigned admiration. "They sure gave us a solid kick that time! We will now take time out for repairs. Also, I'm going to cut our slit down to a width of one kilocycle, if I can possibly figure out a way of working on that narrow a band, and I'm going to step up our shifting speed to a hundred thousand. It's a good thing they built this ship of ours in a lot of layers—if that'd go through the interior we would have been punctured for fair. You might weld up those holes, Mart, while I see what I can do here."

Then Seaton noticed the women, white and trembling, upon a seat.

"'Smatter? Cheer up, kids, you ain't seen nothing yet. That was just a couple of little preliminary love-taps, like two boxers kinda feeling each other out in the first ten seconds of the first round."

"Preliminary love-taps!" repeated Dorothy, looking into Seaton's eyes and being reassured by the serene confidence she read there. "But they hit us, and hurt us badly—why, there's a hole in our Skylark as big as a house, and it goes through four or five layers!"

"Yes, but we're not hurt a bit. They're easily fixed, and we've lost nothing but a few tons of inoson and uranium. We've got lots of spare metal. I don't know what I did to him, any more than he knows what he did to us, but I'll bet my other shirt that he knows he's been nudged!"

Repairs completed and the changes made in the method of projection, Seaton actuated the rapidly-shifting slit and peered through it at the enemy vessel. Finding their screens still up, he directed a complete-coverage attack upon them with four bars, while with the entire massed power of the remaining generators concentrated into one frequency, he shifted that frequency up and down the spectrum, probing, probing, ever probing with that gigantic beam of intolerable energy—feeling for some crack, however slight, into which he could insert that searing sheet of concentrated destruction. Although much of the available power of the Fenachrone was perforce devoted to repelling the continuous attack of the Terrestrials, they maintained an equally continuous attack offensive, and in spite of the narrowness of the open slit and the rapidity with which that slit was changing from frequency to frequency, enough of the frightful forces came through to keep the ultra-powered defensive screens radiating far into the violet—and, the utmost power of the refrigerating system proving absolutely useless against the concentrated beams being employed, mass after mass of inoson was literally blown from the outer and secondary skins of the Skylark by the comparatively tiny jets of force that leaked through the momentarily open slit from time to time, as exact synchronization was accidentally obtained.

Seaton, grimly watching his instruments, glanced at Crane, who, calm but watchful at his console, was repairing the damage as fast as it was done.

"They're sending more stuff, Mart, and it's getting hotter to handle. That means they're building more projectors. We can play that game, too. They're using up their fuel reserves fast; but we're bigger than they are, carry more metal, and it's more efficient metal, too. Only one way out of it, I guess—what say we put in enough generators to smother them down by brute force, no matter how much power it takes?"

"Why don't you use some of those awful copper shells? Or aren't we close enough yet?" Dorothy's low voice came clearly, so utterly silent was that frightful combat.

"Close! We're still better than two hundred thousand light-years apart! There may have been longer-range battles than this somewhere in the Universe, but I doubt it. And as for copper, even if we could get it to them, it'd be just like so many candy kisses compared to the stuff we're both using. Dear girl, there are fields of force extending for thousands of miles from each of these vessels beside which the exact center of the biggest lightning flash you ever saw would be a dead area!"

He set up a series of integrals and, machine after machine, in a space left vacant by the rapidly-vanishing store of uranium, there appeared inside the fourth skin of the Skylark a row of gigantic generators, each one adding its hellish output to the already inconceivable stream of energy being directed at the foe. As that frightful flow increased by leaps and bounds, the intensity of the Fenachrone attack diminished, and finally it ceased altogether as every iota of the enemy's power became necessary for the maintenance of the defenses. Still greater grew the stream of force from the Skylark, and, now that the attack had ceased, Seaton opened the slit wider and stopped its shifting, in order still further to increase the efficiency of his terrible weapon. Face set in a fighting mask and eyes hard as gray iron, deeper and deeper he drove his now irresistible forces. His flying fingers were upon the keys of his console; his keen and merciless eyes were in a secondary projector near the now doomed ship of the Fenachrone, directing masterfully his terrible attack. As the output of his generators still increased, Seaton began to compress a searing hollow sphere of seething energy upon the furiously-straining defensive screens of the Fenachrone. Course after course of the heaviest possible screen was sent out, driven by massed batteries of copper now disintegrating at the rate of tons in every second, only to flare through the ultra-violet and to go down before that dreadful, that irresistible onslaught. Finally, as the inexorable sphere still contracted, the utmost efforts of the defenders could not keep their screens away from their own vessel, and simultaneously the prow and the stern of the Fenachrone cruiser was bared to that awful field of force, in which no possible substance could endure for even the most infinitesimal instant of time.

There was a sudden cessation of all resistance, and those Titanic forces, all directed inward, converged upon a point with a power behind which there was the inconceivable energy of four hundred thousand tons of uranium, being disintegrated at the highest possible rate, short of instant disruption. In that same instant of collapse, the enormous mass of power-copper in the Fenachrone cruiser and the vessel's every atom, alike of structure and contents, also exploded into pure energy at the touch of that unimaginable field of force.

In that awful moment before Seaton could shut off his power it seemed to him that space itself must be obliterated by the very concentration of the unknowable and incalculable forces there unleashed—must be swallowed up and lost in the utterly indescribable brilliance of the field of radiance driven to a distance of millions upon incandescent millions of miles from the place where the last representatives of the monstrous civilization of the Fenachrone had made their last stand against the forces of Universal Peace.



Epilogue

The three-dimensional, moving, talking, almost living picture, being shown simultaneously in all the viewing areas throughout the innumerable planets of the Galaxy, faded out and the image of an aged, white-bearded Norlaminian appeared and spoke in the Galactic language.

"As is customary, the showing of this picture has opened the celebration of our great Galactic holiday, Civilization Day. As you all know, it portrays the events leading up to and making possible the formation of the League of Civilization by a mere handful of planets. The League now embraces all of this, the First Galaxy, and is spreading rapidly throughout the Universe. Varied are the physical forms and varied are the mentalities of our almost innumerable races of beings, but in Civilization we are becoming one, since those backward people who will not co-operate with us are rendered impotent to impede our progress among the more enlightened.

"It is peculiarly fitting that the one who has just been chosen to head the Galactic Council—the first person of a race other than one of those of the Central System to prove himself able to wield justly the vast powers of that office—should be a direct descendant of two of the revered persons whose deeds of olden times we have just witnessed.

"I present to you my successor as Chief of the Galactic Council, Richard Ballinger Seaton, the fourteen hundred sixty-ninth, of Earth."

THE END



SOME REMARKS ON THE "SKYLARK THREE" AND ABOUT ERRORS. A COMPLIMENT TO DR. SMITH'S STORIES.

Editor, AMAZING STORIES:

Dr. Smith, in his foreword to "Skylark Three" mentions two errors which he made knowingly. I think I can recognize the astronomical one, at any rate.

Of course, the acceleration of twice 186,000 miles per second, as used in escaping the field of the great "dud" star, as told in "Skylark of Space" was impossible. Nothing could withstand that strain. Further, no gravitational field could be that intense. It would have exactly the effect Dr. Smith describes and allots to the zone of force in "Skylark Three"—it would make a hole in space and pull the hole in after it. Light would be too heavy to leave the planet. The effect on space would be so great as to curve it so violently as to shut it in about it like a blanket. The dud would be both invisible and unapproachable.

The astronomical error? I wonder how Dr. Smith solved the problem of three—or more—bodies? Osnome is a planet of a sun in a group of seventeen suns, is it not? The gravitational field about even two suns is so exceedingly complex that a planet could take up an orbit only such that one sun was at each of the two foci of the ellipse of its orbit, and then only provided the suns were of very nearly the same mass, and stationary, which in turn means they must have no attraction for each other. No, I think his complex system of seventeen suns would not be so good for planets. Celestial Mechanics won't let them stay there. And I really don't see why it was necessary to have so complex a system.

Further, I wonder if Dr. Smith considered the proposition of his ammonia cooling plant carefully? The ammonia "cooling" plant works only to transmit heat, not to remove it. The heat is removed by it from the inside of an icebox for instance, and put outside, which is what is wanted. However, it must have some place to dump the heat. In the fight with the Mardonalians, Seaton has an arenak cylinder on his compressor, and runs it very heavily, but if he can't get the heat outside the ship, and away from it, he wouldn't cool the machine at all. Since the Mardonalians kept the outside so hot, and the story says the compressor-cooling was accomplished by a water cooler which boiled—some amount of water, too, if it would absorb all the heat of that Mardonalian fleet in any way—and this heat was then merely transferred from outside to inside—where they DIDN'T want it!

Again, in this battle, to protect themselves against ultra-violet radiation, they smear themselves with red paint—presumably because red will stop ultra-violet.

Personalty, I'd have picked some ultra-violet paint—if any were handy as that would reflect the rays. Red wouldn't affect them at all, so far as I can see—he might as well have used blue. What he wanted, was a complementary color of ultra-violet, and I don't believe it is red—green is the complement of red. (Green light won't pass through red glass.)

Dr. Smith invited "knocks" with that foreword of his—I hope I am complying, as an interested reader, and a hopeful scientist. However, my personal opinion has always been that "Skylark of Space" was the best story of scientifiction ever printed, without exception. I have recently changed my opinion, however, since "Skylark Three" has come out.

John W. Campbell, Jr.

Cambridge, Mass.

(This letter from a fellow author is an excellent comment on Dr. Smith's foreword to "Skylark Three." But the writer of this letter is himself inclined to deal with and use very large quantities and high accelerations and velocities in his stories. We are going to let your knocks await a reply from Dr. Smith. The Editor does not desire to find himself between the upper and lower millstones represented by an author and his critic. But you certainly make amends for your criticism by what you say about the merit of "The Skylark Stories." We hope to hear from Dr. Smith.—EDITOR.)

Transcriber's Note & Errata Images have been moved to their appropriate places in the text. All SmallCaps text has been changed to ALL CAPS. The heading and title of Chapter VII were reversed in order in the text. Restored. The following typographical errors have been corrected Error Correction briar; briar, musn't mustn't heads head torpedos torpedoes corruscating coruscating Tarnana Tarnan The attackers "The attackers concience conscience tubular, tubular psssible possible trending tending Normalin Norlamin Seaton Rovol gear-strain gear-train long. long." You are "You are emperically empirically desired." desired. aways always fast. fast." acceleration? acceleration?" Both 'cerebin' and 'cerebrin' were used once each. No changes have been made. Variable hyphenation has not been corrected. Numbers in parentheses in the following table indicate the number of times each form has been used. air-lock (3) airlock (4) air-tight (1) airtight (1) Earth-men (2) Earthmen (1) head-set (1) headset (12) inter-galactic (2) intergalactic (1) stop-watch (1) stopwatch (1) store-rooms (1) storerooms (1)

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