The Building of the sphere I REMEMBER the occasion very distinctly when Cavor told me of his idea of the sphere. He had had intimations of it before, but at the time it seemed to come to him in a rush. We were returning to the bungalow for tea, and on the way he fell humming. Suddenly he shouted, "That's it! That finishes it! A sort of roller blind!"
"Finishes what?" I asked.
"Space - anywhere! The moon."
"What do you mean? "
"Mean? Why - it must be a sphere! That's what I mean!"
I saw I was out of it, and for a time I let him talk in his own fashion. I hadn't the ghost of an idea then of his drift. But after he had taken tea he made it clear to me.
"It's like this," he said. "Last time I ran this stuff that cuts things off from gravitation into a flat tank with an overlap that held it down.
And directly it had cooled and the manufacture was completed all that uproar happened, nothing above it weighed anything, the air went squirting up, the house squirted up, and if the stuff itself hadn't squirted up too, I don't Know what would have happened! But suppose the substance is loose, and quite free to go up? "
"It will go up at once!"
"Exactly. With no more disturbance than firing a big gun."
"But what good will that do? "
"I'm going up with it! "
I put down my teacup and stared at him.
"Imagine a sphere," he explained, "large enough to hold two people and their luggage. It will be made of steel lined with thick glass; it will contain a proper store of solidified air, concentrated food, water distilling apparatus, and so forth. And enamelled, as it were, on the outer steel - "
"Cavorite? "
"Yes."
"But how will you get inside? "
"There was a similar problem about a dumpling."
"Yes, I know. But how?"
"That's perfectly easy. An air-tight manhole is all that is needed. That, of course, will have to be a little complicated; there will have to be a valve, so that things may be thrown out, if necessary, without much loss of air."
"Like Jules Verne's thing in A Trip to the Moon."
But Cavor was not a reader of fiction.
"I begin to see," I said slowly. "And you could get in and screw yourself up while the Cavorite was warm, and as soon as it cooled it would become impervious to gravitation, and off you would fly -"
"At a tangent."
"You would go off in a straight line - " I stopped abruptly. "What is to prevent the thing travelling in a straight line into space for ever?" I asked. "You're not safe to get anywhere, and if you do - how will you get back? "
"I've just thought of that," said Cavor. "That's what I meant when I said the thing is finished. The inner glass sphere can be air-tight, and, except for the manhole, continuous, and the steel sphere can be made in sections, each section capable of rolling up after the fashion of a roller blind. These can easily be worked by springs, and released and checked by electricity conveyed by platinum wires fused through the glass. All that is merely a question of detail. So you see, that except for the thickness of the blind rollers, the Cavorite exterior of the sphere will consist of windows or blinds, whichever you like to call them. Well, when all these windows or blinds are shut, no light, no heat, no gravitation, no radiant energy of any sort will get at the inside of the sphere, it will fly on through space in a straight line, as you say. But open a window, imagine one of the windows open. Then at once any heavy body that chances to be in that direction will attract us "
I sat taking it in.
"You see?" he said.
"Oh, I see."
"Practically we shall be able to tack about in space just as we wish. Get attracted by this and that."
"Oh, yes. That's clear enough. Only - "
" Well? "
"I don't quite see what we shall do it for! It's really only jumping off the world and back again."
"Surely! For example, one might go to the moon."
"And when one got there? What would you find? "
"We should see - Oh! consider the new knowledge."
"Is there air there? "
"There may be."
"It's a fine idea," I said, "but it strikes me as a large order all the same. The moon! I'd much rather try some smaller things first."
"They're out of the question, because of the air difficulty."
"Why not apply that idea of spring blinds - Cavorite blinds in strong steel cases - to lifting weights?"
"It wouldn't work," he insisted. "After all, to go into outer space is not so much worse, if at all, than a polar expedition. Men go on polar expeditions."
"Not business men. And besides, they get paid for polar expeditions. And if anything goes wrong there are relief parties. But this - it's just firing ourselves off the world for nothing."
"Call it prospecting."
"You'll have to call it that. ... One might make a book of it perhaps," I said.
"I have no doubt there will be minerals," said Cavor.
"For example? "
"Oh! sulphur, ores, gold perhaps, possibly new elements."
"Cost of carriage," I said. "You know you're not a practical man. The moon's a quarter of a million miles away."
"It seems to me it wouldn't cost much to cart any weight anywhere if you packed it in a Cavorite case."
I had not thought of that. "Delivered free on head of purchaser, eh? "
"It isn't as though we were confined to the moon."
"You mean? "
"There's Mars - clear atmosphere, novel surroundings, exhilarating sense of lightness. It might be pleasant to go there."
"Is there air on Mars? "
"Oh, yes! "
"Seems as though you might run it as a sanatorium. By the way, how far is Mars? "
"Two hundred million miles at present," said Cavor airily; "and you go close by the sun."
My imagination was picking itself up again. "After all," I said, there's something in these things. There's travel -"
