"Interesting, if true," I remarked.
"And what might Jupiterians be?"
"They might be men, but they're not," he snapped. "They are people from the planet Jupiter. Out of your ignorance you though they might be Martians or Venusians, but you are wrong, for Mars and Venus have people of three dimensions, like ourselves. Jupiterians are entirely different. There are six hundred thousand of them in this Jupiterian airship."
I was so overjoyed at finding someone who could tell me about them, that I didn't think to ask him how he knew all these startling facts.
"Where is the airship you speak of?" I asked.
"There it is," he answered, rather grandiloquently, and pointed to an empty spot on the grass.
I looked carefully, and made out a vast, transparent globe, apparently of glass, which was rapidly becoming visible because of the Chicago dust that was settling upon it. I approached, and touched it with my hand. It gave forth a metallic ring.
"Aha," laughed the professor. "You thought it was glass, but it is made of Jupiterian steel. Look out!"
I sprang back at his warning, and the last hundred thousand leapt out of the globe, passing right through the transparent metal of which it was composed.
"Nom de mademoiselle!" I exclaimed, in astonishment. This was a swear word I had learned in France when I was in the army.
"Nom de mademoiselle!" I repeated, for I liked to show off my knowledge of the language. "How can they pass through the glass without breaking it?"
"Through the Jupiterian steel, you mean," said Professor Nutt, severely. "I told you before that it is not glass. Jupiterian steel has four dimensions, and they pass through the fourth dimension. That is why you can't see the metal, for your eyes are only three-dimensional."
"Are the Jupiterian people four-dimensional?" I asked, awed.
"Certainly," said Nutt, rather irritably.
"Then how is it that I can see them?" I exclaimed triumphantly.
"You see only three of their four dimensions," he replied. "The other one is inside."
I turned to look again at the Jupiterians, who now covered the whole waterfront. One of them sprang lightly, fifty feet into the air, extended a hundred ears like tentacles, and seized an English sparrow. He crushed the sparrow with some score or more of his teeth, which, as I have said, covered his whole body. In less than a minute the poor bird was chewed to pieces, I looked closer, and saw that the Jupiterian had no mouth.
"Nom de mademoiselle!" I exclaimed, for the third time. "How can it get the bird into its stomach?"
"Through the fourth dimension," said Professor Nutt.
It was true. The chewed-up pieces of the bird were suddenly tossed into the air, and the Jupiterian sprang lightly after them. In mid-air he turned inside out, caught the pieces of the bird in his stomach, and lit on the grass again right side up with care.
"Did you see that?" I exclaimed, in a hushed voice. "Why can't I turn inside out that way?"
"Because you are not four-dimensional," replied the professor, a trace of annoyance in his voice. "It is a beautiful thing to have four dimensions," he rhapsodized. "Your Jupiterian is your only true intellectual, for he alone can truly reflect. He turns his gaze in upon himself."
"And sees what be had for breakfast?" I gasped. "And what his neighbors had, too?"
"Your questions are childish," said the professor, wearily. "A Jupiterian, of course, can look into the soul of things, and see what his neighbors had for breakfast, as you so vulgarly express it. But Jupiterians turn their thoughts to higher things."
The creatures now surrounded me, their ears turned inwards, as if they were supplicating.
"What do they want?" I asked the professor.
"They want something to drink," he replied. "They are pointing their ears toward their stomachs to show that they are thirsty."
"Oh," I said, and pointed toward the lake. "There is the fresh, cool water of the lake, if they are thirsty."
"Don't be fantastic," said Professor Nutt. "It isn't water they want."
He fixed his stern, pitiless gaze on my hip pocket. I turned pale, for it was my last pint. But I had to submit. If you have ever had Professor Nutt's cold, accusing eyes on you, you will know just how I felt.
I drew the flask from my pocket, and handed it to the chief Jupiterian, who waggled his ears in joy. Immediately there was pandemonium, if you know what I mean. Ten thousand times ten thousand ears seized the cork, and pulled it out with a resounding pop. One thirsty Jupiterian passed right through the glass into the bottle in his eagerness to get at the contents, and nearly drowned for his pains.
"You see how useful it is to be four-dimensional," remarked the professor. "You could get into any cellar in the world by merely passing through the walls. And into any beer-keg in the same way."
"But," I argued, "how did this—this insect get through the glass into the whisky bottle? Glass has only three dimensions, like everything else in this world."
"Don't call him an insect!" Nutt sharply reprimanded me. "He is a Jupiterian, and as such he is infinitely superior to you and me. He passed through the glass because he is four-dimensional, even though the glass isn't. If you had four dimensions, you could untie any knot by merely passing it through itself. You could turn inside out, or pass through yourself until your right hand became your left hand, and change into your own image as you see it in the looking-glass."
"Nom de mademoiselle!" I exclaimed, for the fourth time.
A distant noise of barking was borne to my ears by the breeze. All the dogs in the city seemed to have gone wild.
"They are disturbed by the talking of the Jupiterians," explained the professor. "It is too high-pitched for clod-hopper human ears to hear, unless they have an unusual range, but the dogs can hear it plainly."
I listened, and finally made out a very shrill humming, higher than any sound I had ever heard before in my life, and infinitely sweet and piercing.
"Ah, I am hearing four-dimensional sounds," I thought, aloud.
"Wrong, as usual," exacerbated the professor, with much heat. "Sound has no dimensions. It proceeds in waves, and bends back upon itself until it meets itself at an infinite distance from the starting point. There are three reasons why you can't hear the music of the spheres: first, because it is bent away from the earth by the force of gravity as it passes the sun; second, because your ears are not attuned to so shrill a sound; and third, because there is no music of the spheres. The first two reasons are really unnecessary, in the light of the third; but a scientific mind such as mine is not content with one reason when three can be adduced just as easily."
"Shades of Sir Oliver Lodge!" I ejaculated.
"Sir Oliver is alive," the professor corrected me. "A man does not become a shade until after his death. Then he
(Continued on page 93)
