The Sky Walker

CHAPTER XVI Invention — A Crook’s Tool!

Dick Benson had guessed the ferry’s new location right on the nose.

The big scow had been towed north, to a point a little above Ludlow where scrubby woods bordered the lake for several miles. There, it had been beached in a small cove. Branches had been cut and strewn on its top so that a cursory search from the air would not have revealed it.

The giant thing was sure to be located in a few days; but the gang using it had every reason to expect that it wouldn’t be found till after they were through with it.

The ferry’s hold was brilliantly lighted by the electric plant run by the diesel. You could see the drums of oil and aviation gasoline, and the small machine shop, and the mysterious vats of water quite plainly. Also, you could see something else, the like of which had never been seen before.

An airplane. But a plane like something out of the book of tomorrow.

It was a big single-motor, cabin job, with conventional lines. But it wasn’t the design that caught and held your eye. It was the material from which it was built.

The plane seemed to be made of glass.

Wings were transparent, fuselage was transparent, seats and pontoons and struts were transparent. It glittered in the improvised hangar like a gigantic dragonfly. Or like a bird of crystal.

The only thing that bulked solid and heavy through the crystalline casing was the motor itself.

Along one wall, staring with fascinated eyes at the plane, were all of Dick Benson’s aides. For once, it looked as if The Avenger had been beaten. Only the pale-eyed man with the prematurely white hair, himself, was not yet in the net.

The giant Smitty leaned his vast back against the timbers of the ferry’s side. He was bound again, with as many coils of rope as would be used to tie an elephant.

Next to Smitty was MacMurdie, burring threats under his breath against the gang who were busying themselves with the plane. Next to him was Josh, who even at such a moment was looking sleepy and thick-witted, and seemed annoyed only at the discomfort of his bonds.

Beside Josh was Rosabel, seeming to be a very frightened Negress. Then came Nellie, helpless and small and appealing-looking — but dangerous as a stick of dynamite if she ever got a chance to act.

The whole bunch of them — helplessly bound — with the gang triumphant.

And there, talking to Carlisle, was the hitherto unsuspected head of the gang, himself: Abel Darcey. That was what infuriated the two girls and Mac and Smitty and Josh more than anything else.

The leader, himself, within a few feet of them, and they could do nothing to scotch him!

Sleek, blond Carlisle was arguing for haste.

“This car ferry’s going to be found very soon. Benson must have reported how it’s being used, and the cops will be hunting it. We’ve got to get through and get away before it is spotted.”

Abel Darcey nodded his distinguished-looking head. It was with a shock that you looked at that fine figure of a man and realized the deviltry he had planned.

“You can rest your mind about the time element,” the five trussed aides of The Avenger heard Darcey say. “We are almost through. In fact, when we leave here in a few hours, we will leave for the last time.”

Carlisle’s sleek brows went up.

“We have done enough to the railroad,” said Darcey. “That one last wreck will break it. The stockholders will rush to sell, at a bargain figure, and so the road becomes mine.”

“But the rest?” said Carlisle.

“We have built up the ‘foreign-invasion’ myth almost enough. We will topple one more building. Then there won’t need to be any more catastrophes. The story about invasion by a secret enemy will slowly die. But not for a good many years will any steel but Catawbi steel be used for building purposes in the Middle West. People won’t have any other metal but that which stood up in the collapses.”

“You’ll get hundreds of millions out of it,” Carlisle said, a little resentfully.

“You, and all the rest, will be rich beyond your dreams,” Darcey retorted coldly. “You have no complaint to make.”

“Oh, no, not at all,” Carlisle’s voice was hurried. It was evident that he didn’t want to irritate this man.

Darcey’s eyes swept over the bound figures propped against the side of the ferry.

“These people have been annoying,” he said. “But they won’t bother us any more!”

“This plane, boss. What’ll we do with her after tonight?”

Darcey’s eyes ranged over the glittering ship.

“We will take her out to the middle of the lake and sink her, of course. Along with the little device that has been such an important cargo. The plane, and that invention of the Gants, are the only direct clues against us. So we shall destroy them.”

“Seems a shame to sink that plane,” said Carlisle.

“It would be more of a shame to have it found — and traced to me! Are the men ready to prepare it for this evening’s work? All right. Have them go ahead, then.”

The gang had been swarming over wings and fuselage like ants over a bit of bread. Their swarming began to have more purpose now.

They had been loosening kingbolts and struts. Now they began taking the ship deftly apart.

The light hand-cranes were wheeled to the plane. The hooks were lowered to the left wing, raised, and the wing came off. The right wing was removed.

Men inside were taking out the seats — everything movable. The pontoons were taken off. In a little while the ship was dismantled and lay all over the ferry floor.

And then began a process that seemed insane.

The men, working like beavers, began dipping the parts of the plane, piece by piece into the great shallow vats of water.

First, one would dip into the drum that Smitty had discovered held the whitish, lardy-looking substance. He would get a piece as big as a walnut, and throw it into the vat being used. Then the crew would lower wing, or fuselage, or seats. The lowered part would be raised, dripping, and the process would be repeated.

It seemed a mad, reasonless thing to do. But as the process went on, and part after part was dipped time and again, the purpose of it became apparent.

With every dipping, the part in question became less easily seen. It became more invisible.

Mac gasped, as the key to the whole performance came home to his chemist’s brain at last.

“Of course!” he muttered. “The letters on the drum… IUM. EARA. And the little strip of Glassite that Rosabel told of being delivered to the Gant brothers’ laboratory! Of course!”

“What are you mumbling about?” said Smitty.

“The reason for this dippin’!” Mac said. “The chief’s known from the start. Of course! He must have known the minute you told of that drum of whitish stuff with those letters on the side that hadn’t been quite scratched off! And I was too dumb to tumble to it.”

“You’re dumb, all right,” grated the giant. “I won’t argue with you there. But what—”

The parts of the plane had been dipped perhaps thirty times by now. And they had all become utterly transparent.

The word, transparent, is loosely used. Actually, nothing is absolutely transparent. Not even glass.

It isn’t generally realized, simply because most people don’t think about the matter much — but an object that is completely transparent would be completely invisible.

This plane, for instance.

It seemed to be made of glass. And at first thought, you’d get the idea that a glass airplane wouldn’t be seen in the sky because you could look right through it and see the clouds on the other side. But it wouldn’t work out that way.

Glass is fairly transparent, but its reflective powers are bad. Or, rather, too good. Every ray of light striking glass at an angle is reflected. So a glass plane in the sky would be as plainly seen as any other ship. More plainly, perhaps: every polished surface on it would constantly be reflecting sunlight till the thing hung like a glittering diamond in the heavens.

But the dipping process to which the glassy substance of the plane was being subjected was taking away its reflective powers!

Part after part, as it emerged from trip after trip into a vat, with the whitish stuff being put in first, was being rendered more and more truly invisible. That is — it transmitted all light, instead of giving its presence away by reflecting some of it.

Finally they were done. And a miracle had been accomplished.

Smitty and Mac stared with bulging eyes while men carried the fuselage back to the center of the hangar. They seemed to be laboring along under nothing but thin air.

They caught up a wing and bolted it into place. They seemed to be kneeling in empty air, working with nothing.

Finally the plane was assembled again.

Faintly, very faintly, because of a few metal bolts and clips where strength needed good chrome steel, you could see a plane there. But the only thing you could really see was the motor, big and solid and prosaic in the almost invisible nose.

“The skywalker!” whispered Mac.

“Huh?” said Smitty.

“When that thing’s a mile or more up,” Mac explained, “all that could be seen would be the motor and the pilot. Two little dots in the air. Exceptionally good eyes could see the dots. An’ ’twould look like a man walkin’ in thin air, an eighth of a mile to a stride, an’ pushin’ somethin’ like a barrel — the motor — ahead of him. So we were told there was a man ‘walkin’ in the sky.’ ”

“Yeah, sure,” said Smitty. “I can see that, all right. But how do they do this?”

“Barium stearate,” said Mac. “That’s the whitish, fatty stuff in the metal drum. For some time now, a few chemists have known what barium stearate does to glass.

“Ye put a little barium stearate into plain water. It spreads into a film on the water so thin ye can’t see it. Ye dip glass into the pan. The barium stearate forms a transparent coating over the glass only a molecule in thickness. Ye do that thirty or forty times and ye have a shell over the glass about a millionth of an inch thick that makes it absolutely transparent — kills light reflection — an’ hence makes it invisible.”

“But that stuff can’t be glass,” argued Smitty. “You couldn’t make a plane out of glass. It’s too brittle.”

“Glassite,” Mac corrected him. “The stuff the Warwick Corporation has recently perfected. It’s as clear as glass, but as tough as steel. A brand-new plastic. That was one of the Gant brothers’ inventions: they found that ye can treat Glassite with barium stearate to make it invisible, just as ye can treat glass. Only ye can make things out of Glassite that you couldn’t out of ordinary glass. Like planes.”

“And the other invention of the Gant brothers?” said Smitty.

“It’s no doubt the thing that devil, Darcey, called ‘the little device that has been such an important cargo’ in the invisible plane. What that is, we can’t guess yet. But it’s somethin’ that can disintegrate solid steel from a mile or two up in the air.”

They stared for a moment more at the plane — wings, fuselage, pontoons, even seats, made of the stuff that had been rendered almost invisible by the barium stearate.

Then their eyes swung suddenly toward the lake end of the hangar. Toward the broken plank there that made such an innocent-looking small door.

The eyes of the gang swung that way, too. And then they were jumping around like a bunch of startled fawns, with guns in their hands that they obviously hated to use for fear the shots would be heard on some distant farm and the new location of the ferry prematurely discovered.

A man was coming in the door, dripping, of course, because you had to swim to get to it from shore.

He was an elderly man, with thin gray hair and a pinkish face, drawn now from fear and rage. His expensive clothes were ripped from passage through the underbrush around the beached ferry. There were bruises and blood on his face.

“Carlisle!” he yelled. “Hold that man calling himself Darcey! Get him — I say!”

The gang gaped at each other. And Smitty and Mac and Josh and the two girls stared with dawning amazement at the man who had been talking to Carlisle.

That man bent like a flash, straightened. There was a flick of his arm, and something thudded lightly into the timbers between Rosabel and Nellie Gray’s bound figures.

Then the man with the bruised face rushed from the door.