He turned partly from me and began to whistle. I heard the patter of feet, the panting of a heated animal, and the unmistakable yelp of a dog. Then Paul stooped down and apparently fondled the empty air.

"Here! Give me your fist."

And he rubbed my hand over the cold nose and jowls of a dog. A dog it certainly was, with the shape and the smooth, short coat of a pointer.

Suffice to say, I speedily recovered my spirits and control. Paul put a collar about the animal's neck and tied his handkerchief to its tail.

And then was vouchsafed us the remarkable sight of an empty collar and a waving handkerchief cavorting over the fields. It was something to see that collar and handkerchief pin a bevy of quail in a clump of locusts and remain rigid and immovable till we had flushed the birds.

Now and again the dog emitted the vari-colored light-flashes I have mentioned. The one thing, Paul explained, which he had not antic.i.p.ated and which he doubted could be overcome.

"They're a large family," he said, "these sun dogs, wind dogs, rainbows, halos, and parhelia. They are produced by refraction of light from mineral and ice crystals, from mist, rain, spray, and no end of things; and I am afraid they are the penalty I must pay for transparency. I escaped Lloyd's shadow only to fetch up against the rainbow flash."

A couple of days later, before the entrance to Paul's laboratory, I encountered a terrible stench. So overpowering was it that it was easy to discover the source--a ma.s.s of putrescent matter on the doorstep which in general outlines resembled a dog.

Paul was startled when he investigated my find. It was his invisible dog, or rather, what had been his invisible dog, for it was now plainly visible. It had been playing about but a few minutes before in all health and strength. Closer examination revealed that the skull had been crushed by some heavy blow. While it was strange that the animal should have been killed, the inexplicable thing was that it should so quickly decay.

"The reagents I injected into its system were harmless," Paul explained.

"Yet they were powerful, and it appears that when death comes they force practically instantaneous disintegration. Remarkable! Most remarkable!

Well, the only thing is not to die. They do not harm so long as one lives. But I do wonder who smashed in that dog's head."

Light, however, was thrown upon this when a frightened housemaid brought the news that Gaffer Bedshaw had that very morning, not more than an hour back, gone violently insane, and was strapped down at home, in the huntsman's lodge, where he raved of a battle with a ferocious and gigantic beast that he had encountered in the Tichlorne pasture. He claimed that the thing, whatever it was, was invisible, that with his own eyes he had seen that it was invisible; wherefore his tearful wife and daughters shook their heads, and wherefore he but waxed the more violent, and the gardener and the coachman tightened the straps by another hole.

Nor, while Paul Tichlorne was thus successfully mastering the problem of invisibility, was Lloyd Inwood a whit behind. I went over in answer to a message of his to come and see how he was getting on. Now his laboratory occupied an isolated situation in the midst of his vast grounds. It was built in a pleasant little glade, surrounded on all sides by a dense forest growth, and was to be gained by way of a winding and erratic path. But I have travelled that path so often as to know every foot of it, and conceive my surprise when I came upon the glade and found no laboratory. The quaint shed structure with its red sandstone chimney was not. Nor did it look as if it ever had been. There were no signs of ruin, no debris, nothing.

I started to walk across what had once been its site. "This," I said to myself, "should be where the step went up to the door." Barely were the words out of my mouth when I stubbed my toe on some obstacle, pitched forward, and b.u.t.ted my head into something that FELT very much like a door. I reached out my hand. It WAS a door. I found the k.n.o.b and turned it. And at once, as the door swung inward on its hinges, the whole interior of the laboratory impinged upon my vision. Greeting Lloyd, I closed the door and backed up the path a few paces. I could see nothing of the building. Returning and opening the door, at once all the furniture and every detail of the interior were visible. It was indeed startling, the sudden transition from void to light and form and color.

"What do you think of it, eh?" Lloyd asked, wringing my hand. "I slapped a couple of coats of absolute black on the outside yesterday afternoon to see how it worked. How's your head? you b.u.mped it pretty solidly, I imagine."

"Never mind that," he interrupted my congratulations. "I've something better for you to do."

While he talked he began to strip, and when he stood naked before me he thrust a pot and brush into my hand and said, "Here, give me a coat of this."

It was an oily, sh.e.l.lac-like stuff, which spread quickly and easily over the skin and dried immediately.

"Merely preliminary and precautionary," he explained when I had finished; "but now for the real stuff."

I picked up another pot he indicated, and glanced inside, but could see nothing.

"It's empty," I said.

"Stick your finger in it."

I obeyed, and was aware of a sensation of cool moistness. On withdrawing my hand I glanced at the forefinger, the one I had immersed, but it had disappeared. I moved and knew from the alternate tension and relaxation of the muscles that I moved it, but it defied my sense of sight. To all appearances I had been shorn of a finger; nor could I get any visual impression of it till I extended it under the skylight and saw its shadow plainly blotted on the floor.

Lloyd chuckled. "Now spread it on, and keep your eyes open."

I dipped the brush into the seemingly empty pot, and gave him a long stroke across his chest. With the pa.s.sage of the brush the living flesh disappeared from beneath. I covered his right leg, and he was a one-legged man defying all laws of gravitation. And so, stroke by stroke, member by member, I painted Lloyd Inwood into nothingness. It was a creepy experience, and I was glad when naught remained in sight but his burning black eyes, poised apparently unsupported in mid-air.

"I have a refined and harmless solution for them," he said. "A fine spray with an air-brush, and presto! I am not."

This deftly accomplished, he said, "Now I shall move about, and do you tell me what sensations you experience."

"In the first place, I cannot see you," I said, and I could hear his gleeful laugh from the midst of the emptiness. "Of course," I continued, "you cannot escape your shadow, but that was to be expected. When you pa.s.s between my eye and an object, the object disappears, but so unusual and incomprehensible is its disappearance that it seems to me as though my eyes had blurred. When you move rapidly, I experience a bewildering succession of blurs. The blurring sensation makes my eyes ache and my brain tired."

"Have you any other warnings of my presence?" he asked.

"No, and yes," I answered. "When you are near me I have feelings similar to those produced by dank warehouses, gloomy crypts, and deep mines. And as sailors feel the loom of the land on dark nights, so I think I feel the loom of your body. But it is all very vague and intangible."

Long we talked that last morning in his laboratory; and when I turned to go, he put his unseen hand in mine with nervous grip, and said, "Now I shall conquer the world!" And I could not dare to tell him of Paul Tichlorne's equal success.

At home I found a note from Paul, asking me to come up immediately, and it was high noon when I came spinning up the driveway on my wheel. Paul called me from the tennis court, and I dismounted and went over. But the court was empty. As I stood there, gaping open-mouthed, a tennis ball struck me on the arm, and as I turned about, another whizzed past my ear. For aught I could see of my a.s.sailant, they came whirling at me from out of s.p.a.ce, and right well was I peppered with them. But when the b.a.l.l.s already flung at me began to come back for a second whack, I realized the situation. Seizing a racquet and keeping my eyes open, I quickly saw a rainbow flash appearing and disappearing and darting over the ground. I took out after it, and when I laid the racquet upon it for a half-dozen stout blows, Paul's voice rang out:

"Enough! Enough! Oh! Ouch! Stop! You're landing on my naked skin, you know! Ow! O-w-w! I'll be good! I'll be good! I only wanted you to see my metamorphosis," he said ruefully, and I imagined he was rubbing his hurts.

A few minutes later we were playing tennis--a handicap on my part, for I could have no knowledge of his position save when all the angles between himself, the sun, and me, were in proper conjunction. Then he flashed, and only then. But the flashes were more brilliant than the rainbow--purest blue, most delicate violet, brightest yellow, and all the intermediary shades, with the scintillant brilliancy of the diamond, dazzling, blinding, iridescent.

But in the midst of our play I felt a sudden cold chill, reminding me of deep mines and gloomy crypts, such a chill as I had experienced that very morning. The next moment, close to the net, I saw a ball rebound in mid-air and empty s.p.a.ce, and at the same instant, a score of feet away, Paul Tichlorne emitted a rainbow flash. It could not be he from whom the ball had rebounded, and with sickening dread I realized that Lloyd Inwood had come upon the scene. To make sure, I looked for his shadow, and there it was, a shapeless blotch the girth of his body, (the sun was overhead), moving along the ground. I remembered his threat, and felt sure that all the long years of rivalry were about to culminate in uncanny battle.

I cried a warning to Paul, and heard a snarl as of a wild beast, and an answering snarl. I saw the dark blotch move swiftly across the court, and a brilliant burst of vari-colored light moving with equal swiftness to meet it; and then shadow and flash came together and there was the sound of unseen blows. The net went down before my frightened eyes. I sprang toward the fighters, crying:

"For G.o.d's sake!"

But their locked bodies smote against my knees, and I was overthrown.

"You keep out of this, old man!" I heard the voice of Lloyd Inwood from out of the emptiness. And then Paul's voice crying, "Yes, we've had enough of peacemaking!"

From the sound of their voices I knew they had separated. I could not locate Paul, and so approached the shadow that represented Lloyd. But from the other side came a stunning blow on the point of my jaw, and I heard Paul scream angrily, "Now will you keep away?"

Then they came together again, the impact of their blows, their groans and gasps, and the swift flashings and shadow-movings telling plainly of the deadliness of the struggle.

I shouted for help, and Gaffer Bedshaw came running into the court. I could see, as he approached, that he was looking at me strangely, but he collided with the combatants and was hurled headlong to the ground. With despairing shriek and a cry of "O Lord, I've got 'em!" he sprang to his feet and tore madly out of the court.

I could do nothing, so I sat up, fascinated and powerless, and watched the struggle. The noonday sun beat down with dazzling brightness on the naked tennis court. And it was naked. All I could see was the blotch of shadow and the rainbow flashes, the dust rising from the invisible feet, the earth tearing up from beneath the straining foot-grips, and the wire screen bulge once or twice as their bodies hurled against it. That was all, and after a time even that ceased. There were no more flashes, and the shadow had become long and stationary; and I remembered their set boyish faces when they clung to the roots in the deep coolness of the pool.

They found me an hour afterward. Some inkling of what had happened got to the servants and they quitted the Tichlorne service in a body.

Gaffer Bedshaw never recovered from the second shock he received, and is confined in a madhouse, hopelessly incurable. The secrets of their marvellous discoveries died with Paul and Lloyd, both laboratories being destroyed by grief-stricken relatives. As for myself, I no longer care for chemical research, and science is a tabooed topic in my household. I have returned to my roses. Nature's colors are good enough for me.

ALL GOLD CANYON

It was the green heart of the canyon, where the walls swerved back from the rigid plan and relieved their harshness of line by making a little sheltered nook and filling it to the brim with sweetness and roundness and softness. Here all things rested. Even the narrow stream ceased its turbulent down-rush long enough to form a quiet pool. Knee-deep in the water, with drooping head and half-shut eyes, drowsed a red-coated, many-antlered buck.

On one side, beginning at the very lip of the pool, was a tiny meadow, a cool, resilient surface of green that extended to the base of the frowning wall. Beyond the pool a gentle slope of earth ran up and up to meet the opposing wall. Fine gra.s.s covered the slope--gra.s.s that was spangled with flowers, with here and there patches of color, orange and purple and golden. Below, the canyon was shut in. There was no view. The walls leaned together abruptly and the canyon ended in a chaos of rocks, moss-covered and hidden by a green screen of vines and creepers and boughs of trees. Up the canyon rose far hills and peaks, the big foothills, pine-covered and remote. And far beyond, like clouds upon the border of the slay, towered minarets of white, where the Sierra's eternal snows flashed austerely the blazes of the sun.

There was no dust in the canyon. The leaves and flowers were clean and virginal. The gra.s.s was young velvet. Over the pool three cottonwoods sent their scurvy fluffs fluttering down the quiet air. On the slope the blossoms of the wine-wooded manzanita filled the air with springtime odors, while the leaves, wise with experience, were already beginning their vertical twist against the coming aridity of summer. In the open s.p.a.ces on the slope, beyond the farthest shadow-reach of the manzanita, poised the mariposa lilies, like so many flights of jewelled moths suddenly arrested and on the verge of trembling into flight again. Here and there that woods harlequin, the madrone, permitting itself to be caught in the act of changing its pea-green trunk to madder-red, breathed its fragrance into the air from great cl.u.s.ters of waxen bells.

Creamy white were these bells, shaped like lilies-of-the-valley, with the sweetness of perfume that is of the springtime.