"Just as the higher-powered a radio set is, the more perfect must be its shielding?"

"Yes. Just as a trace of any gas will destroy the usefulness of your most sensitive vacuum tubes, and just as imperfect shielding will allow interfering waves to enter sensitive electrical apparatus--in that same fashion will even the slightest ether vibration interfere with the operation of the extremely sensitive fields and lenses of force which must be used in controlling forces of the higher orders."

"You haven't tested the theory of the fourth order yet, have you?"

"No, but that is unnecessary. The theory of the fourth order is not really theory at all--it is mathematical fact. Although we have never been able to generate them, we know exactly the forces you use in your ship of s.p.a.ce, and we can tell you of some thousands of others more or less similar and also highly useful forces which you have not yet discovered, but are allowing to go to waste. We know exactly what they are, how to liberate and control them, and how to use them. In fact, in the work which we are to begin today, we shall use but little ordinary power: almost all our work will be done by fourth-order forces, liberated from copper by means of the Rovolon you have given me. But here we are at my laboratory. You already know that the best way to learn is by doing, and we shall begin at once."

The flier alighted upon a lawn quite similar to the one before the observatory of Orlon, and the scientist led his Earthly guest through the main entrance of the imposing structure of vari-colored marble and gleaming metal and into the vast, gla.s.s-lined room that was his laboratory. Great benches lined the walls, and there were hundreds of dials, meters, tubes, transformers and other instruments, whose uses Seaton could not even guess.

Rovol first donned a suit of transparent, flexible material, of a deep golden color, instructing Seaton to do the same; explaining that much of the work would be with dangerous frequencies and with high pressures, and that the suits were not only absolute insulators against electricity, heat, and sound, but were also ray-filters proof against any harmful radiations. As each helmet was equipped with radiophones, conversation was not interfered with in the least.

Rovol took up a tiny flash-pencil, and with it deftly cut off a bit of Rovolon, almost microscopic in size. This he placed upon a great block of burnished copper, and upon it played a force. As he manipulated two levers, two more beams of force flattened out the particle of metal, spread it out over the copper, and forced it into the surface of the block until the thin coating was at every point in molecular contact with the copper beneath it--a perfect job of plating, and one done in the twinkling of an eye. He then cut out a piece of the treated copper the size of a pea, and other forces rapidly built around it a structure of coils and metallic tubes. This apparatus he suspended in the air at the extremity of a small beam of force. The block of copper was next cut in two, and Rovol's fingers moved rapidly over the keys of a machine which resembled slightly an overgrown and exceedingly complicated book-keeping machine. Streams and pencils of force flashed and crackled, and Seaton saw raw materials transformed into a complete power-plant, in its center the two-hundred-pound lump of plated copper, where an instant before there had been only empty s.p.a.ce upon the ma.s.sive metal bench.

Rovol's hands moved rapidly from keys to dials and back, and suddenly a zone of force, as large as a basketball appeared around the apparatus poised in the air.

"But it'll fly off and we can't stop it with anything," Seaton protested, and it did indeed dart rapidly upward.

The old man shook his head as he manipulated still more controls, and Seaton gasped as nine stupendous beams of force hurled themselves upon that brilliant spherical mirror of pure energy, seized it in mid-flight, and shaped it resistlessly, under his bulging eyes, into a complex geometrical figure of precisely the desired form.

Lurid violet light filled the room, and Seaton turned towards the bar.

That two-hundred-pound ma.s.s of copper was shrinking visibly, second by second, so vast were the forces being drawn from it, and the searing, blinding light would have been intolerable but for the protective color-filters of his helmet. Tremendous flashes of lightning ripped and tore from the relief-points of the bench to the ground-rods, which flared at blue-white temperature under the incessant impacts. Knowing that this corona-loss was but an infinitesimal fraction of the power being used, Seaton's very mind staggered as he strove to understand the magnitude of the forces at work upon that stubborn sphere of energy.

The aged scientist used no tools whatever, as we understand the term.

His laboratory was a power-house; at his command were the stupendous forces of a battery of planetoid acc.u.mulators, and added to these were the fourth-order, ninth-magnitude forces of the disintegrating copper bar. Electricity, protelectricity, and fourth-order rays, under millions upon millions of kilovolts of pressure, leaped to do the bidding of that wonderful brain, stored with the acc.u.mulated knowledge of countless thousands of years of scientific research. Watching the ancient physicist work, Seaton compared himself to a schoolboy mixing chemicals indiscriminately and ignorantly, with no knowledge whatever of their properties, occasionally obtaining a reaction by pure chance. Whereas he had worked with intra-atomic energy schoolboy fashion, the master craftsman before him knew every reagent, every reaction, and worked with known and thoroughly familiar agencies to bring about his exactly predetermined ends--just as calmly certain of the results as Seaton himself would have been in his own laboratory, mixing equivalent quant.i.ties of solutions of barium chloride and of sulphuric acid to obtain a precipitate of barium sulphate.

[Ill.u.s.tration: _Hour after hour Rovol labored on, oblivious to the pa.s.sage of time in his zeal of accomplishment, the while carefully instructing Seaton, who watched every step with intense interest...._]

Hour after hour Rovol labored on, oblivious to the pa.s.sage of time in his zeal of accomplishment, the while carefully instructing Seaton, who watched every step with intense interest and did everything possible for him to do. Bit by bit a towering structure arose in the middle of the laboratory. A metal foundation supported a ma.s.sive compound bearing, which in turn carried a tubular network of latticed metal, mounted like an immense telescope. Near the upper, outer end of this openwork tube a group of nine forces held the field of force rigidly in place in its axis; at the lower extremity were mounted seats for two operators and the control panels necessary for the operation of the intricate system of forces and motors which would actuate and control that gigantic projector. Immense hour and declination circles could be read by optical systems from the operators' seats--circles fully forty feet in diameter, graduated with incredible delicacy and accuracy into decimal fractions of seconds of arc, and each driven by variable-speed motors through gear-trains and connections having no backlash whatever.

While Rovol was working upon one of the last instruments to be installed upon the controlling panel a mellow note sounded throughout the building, and he immediately ceased his labors and opened the master-switches of his power plants.

"You have done well, youngster," he congratulated his helper, as he began to take off his protective covering, "Without your aid I could not have accomplished nearly this much during one period of labor. The periods of exercise and of relaxation are at hand--let us return to the house of Orlon, where we all shall gather to relax and to refresh ourselves for the labors of tomorrow."

"But it's almost done!" protested Seaton. "Let's finish it up and shoot a little juice through it, just to try it out."

"There speaks the rashness and impatience of youth," rejoined the scientist, calmly removing the younger man's suit and leading him out to the waiting airboat. "I read in your mind that you are often guilty of laboring continuously until your brain loses its keen edge. Learn now, once and for all, that such conduct is worse than foolish--it is criminal. We have labored the full period. Laboring for more than that length of time without recuperation results in a loss of power which, if persisted in, wreaks permanent injury to the mind; and by it you gain nothing. We have more than ample time to do that which must be done--the fifth-order projector shall be completed before the warning torpedo shall have reached the planet of the Fenachrone--therefore over-exertion is unwarranted. As for testing, know now that only mechanisms built by bunglers require testing. Properly built machines work properly."

"But I'd have liked to see it work just once, anyway," lamented Seaton as the small airship tore through the air on its way back to the observatory.

"You must cultivate calmness, my son, and the art of relaxation. With those qualities your race can easily double its present span of useful life. Physical exercise to maintain the bodily tissues at their best, and mental relaxation following mental toil--these things are the secrets of a long and productive life. Why attempt to do more than can be accomplished efficiently? There is always tomorrow. I am more interested in that which we are now building than you can possibly be, since many generations of the Rovol have antic.i.p.ated its construction; yet I realize that in the interest of our welfare and for the progress of civilization, today's labors must not be prolonged beyond today's period of work. Furthermore, you yourself realize that there is no optimum point at which any task may be interrupted. Short of final completion of any project, one point is the same as any other. Had we continued, we would have wished to continue still farther, and so on without end."

"You're probably right, at that," the impetuous chemist conceded, as their craft came to earth before the observatory.

Crane and Orlon were already in the common room, as were the scientists Seaton already knew, as well as a group of women and children still strangers to the Terrestrials. In a few minutes Orlon's companion, a dignified, white-haired woman, entered; accompanied by Dorothy, Margaret, and a laughing, boisterous group of men and women from the Country of Youth. Introductions over, Seaton turned to Crane.

"How's every little thing, Mart?"

"Very well indeed. We are building an observatory in s.p.a.ce--or rather, Orlon is building it and I am doing what little I can to help him. In a few days we shall be able to locate the system of the Fenachrone. How is your work progressing?"

"Smoother than a kitten's ear. Got the fourth-order projector about done. We're going to project a fourth-order force out to grab us some dense material, a pretty close approach to pure neutronium. There's nothing dense enough around here, even in the core of the central sun, so we're going out to a white dwarf star--one a good deal like the companion star to Sirius in Canis Major--get some material of the proper density from its core, and convert our sender into a fifth-order machine. Then we can really get busy--go places and do things."

"Neutronium? Pure ma.s.s?" queried Crane, "I have been under the impression that it does not exist. Of what use can such a substance be to you?"

"Can't get pure neutronium, of course--couldn't use it if we could. What we need and are going to get is a material of about two and a half million specific gravity. Got to have it for lenses and controls for the fifth-order forces. Those rays go right through anything less dense without measurable refraction. But I see Rovol's giving me a nasty look.

He's my boss on this job, and I imagine this kind of talk's barred during the period of relaxation, as being work. That so, chief?"

"You know that it is barred, you incorrigible young cub!" answered Rovol, with a smile.

"All right, boss; one more little infraction and I'll shut up like a clam. I'd like to know what the girls have been doing."

"We've been having a wonderful time!" Dorothy declared. "We've been designing fabrics and ornaments and jewels and things. Wait 'til you see 'em!"

"Fine! All right, Orlon, it's your party--what to do?"

"This is the time of exercise. We have many forms, most of which are unfamiliar to you. You all swim, however, and as that is one of the best of exercises, I suggest that we all swim."

"Lead us to it!" Seaton exclaimed, then his voice changed abruptly.

"Wait a minute--I don't know about our swimming in copper sulphate solution."

"We swim in fresh water as often as in salt, and the pool is now filled with distilled water."

The Terrestrials quickly donned their bathing suits and all went through the observatory and down a winding path, bordered with the peculiarly beautiful scarlet and green shrubbery, to the "pool"--an artificial lake covering a hundred acres, its polished metal bottom and sides strikingly decorated with jewels and glittering tiles in tasteful yet contrasting inlaid designs. Any desired depth of water was available and plainly marked, from the fenced-off shallows where the smallest children splashed to the forty feet of liquid crystal which received the diver who cared to try his skill from one of the many spring-boards, flying rings, and catapults which rose high into the air a short distance away from the entrance.

Orlon and the others of the older generation plunged into the water without ado and struck out for the other sh.o.r.e, using a fast double-overarm stroke. Swimming in a wide circle they came out upon the apparatus and went through a series of methodical dives and gymnastic performances. It was evident that they swam, as Orlon had intimated, for exercise. To them, exercise was a necessary form of labor--labor which they performed thoroughly and well--but nothing to call forth the whole-souled enthusiasm they displayed in their chosen fields of mental effort.

The visitors from the Country of Youth, however, locked arms and sprang to surround the four Terrestrials, crying, "Let's do a group dive!"

"I don't believe that I can swim well enough to enjoy what's coming,"

whispered Margaret to Crane, and they slipped into the pool and turned around to watch. Seaton and Dorothy, both strong swimmers, locked arms and laughed as they were encircled by the green phalanx and swept out to the end of a dock-like structure and upon a catapult.

"Hold tight, everybody!" someone yelled, and interlaced, straining arms and legs held the green and white bodies in one motionless group as a gigantic force hurled them fifty feet into the air and out over the deepest part of the pool. There was a mighty splash and a miniature tidal wave as that ma.s.s of humanity struck the water. Many feet they went down before the cordon was broken and the individual units came to the surface. Then pandemonium reigned. Vigorous informal games, having to do with floating and sinking b.a.l.l.s and effigies: pushball, in which the players never seemed to know, or to care, upon which side they were playing; water-fights and ducking contests.... A green mermaid, having felt the incredible power of Seaton's arms as he tossed her lightly away from a goal he was temporarily defending, put both her small hands around his biceps wonderingly, amazed at a strength unknown and impossible upon her world; then playfully tried to push him under.

Failing, she called for help.

"He's needed a good ducking for ages!" Dorothy cried, and she and several other girls threw themselves upon him. Over and around him the lithe forms flashed, while the rest of the young people splashed water impartially over all the combatants and cheered them on. In the midst of the battle the signal sounded to end the period of exercise.

"Saved by the bell," Seaton laughed as, thoroughly ducked and almost half drowned, he was allowed to swim ash.o.r.e.

When all had returned to the common room of the observatory and had seated themselves, Orlon took out his miniature ray-projector, no larger than a fountain pen, and flashed it briefly upon one of the hundreds of b.u.t.ton-like lenses upon the wall. Instantly each chair converted itself into a form-fitting divan, inviting complete repose.

"I believe that you of Earth would perhaps enjoy some of our music during this, the period of relaxation and repose--it is so different from your own," Orlon remarked, as he again manipulated his tiny force-tube.

Every light was extinguished and there was felt a profoundly deep vibration--a note so low as to be palpable rather than audible; and simultaneously the utter darkness was relieved by a tinge of red so dark as to be barely perceptible, while a peculiar somber fragrance pervaded the atmosphere. The music rapidly ran the gamut to the limit of audibility and, in the same tempo, the lights traversed the visible spectrum and disappeared. Then came a crashing chord and a vivid flare of blended light; ushering in an indescribable symphony of sound and color, accompanied by a slower succession of shifting, blending odors.