I woke with a bandaged hand and four fingers shortened by the length of the nails. It was late afternoon and the chief was poking the sky with little rods. He stopped when he saw I was conscious, asked about my exact sensations before fainting, wrote them down, then pointed east and said, “We are no longer alone.”
Several towers had sprouted surprisingly in the last three days. One of them, by employing acrobats as construction workers, had gained a mile-high superstructure of bamboo canes. But the big cooperative summit, though still the second highest, had grown very little in spite of its early start. And now the vastest smokelift I have ever seen was tethered to the top of that summit by many cables. The bag was shaped like an upside-down pyramid. The top surface was level with our platform, and in the centre a crouching figure handled something which flared and sparkled. We heard a brief humming of almost painful intensity and above the lift appeared a white mark which sped across the sky and curved down into a cloud which hid the horizon. The chief said, “He’s started testing it with fire. I’m leaving that till last.”
Next day the company’s directors came up to the platform and stared at the sky with all the expressions of men faced by a beautiful woman. The eyes and mouths of many gaped very wide and a few were moved to tears. The president kept sighing and nodding as if the sky was defeating him in a crucial argument. The commander of the armed forces frowned and fidgeted as if it was wasting his time; he was more interested in the cooperative lift, on which a group of men like our own had gathered. Only the chief looked eager and happy. He grinned determinedly upward as if saying, “Yes, sky, you dazzle and baffle other men, but not me. You won’t be able to keep anything from me.”
We went down to the president’s office, sat round the table, and the chief read out this report.
“Gentlemen, you have just seen a transparent surface which encloses the earthly globe at an altitude of 22 parasangs, or 572 stadia, or 62,920 fathoms. Although this surface is in rapid movement it feels beguilingly smooth, soft and lukewarm if touched gently, but repels anything solid which presses hard, dissolving flesh, crumbling bone and wood to powder, and making stones, metal and crystals explode with a violence growing greater with the density of the mineral and the force driving it into contact. These explosions exert downward with no effect upon the heavenly surface, a fact with political consequences. Less advanced summits are building catapults at their tops with the clear intention of testing the sky from a distance by throwing things at it. This will cause blasts big enough to damage the advanced summits. We should make it plain that we will regard such tests as acts of war. When jets of water, ink, acid, mercury and molten metal strike the surface it absorbs them without stain or alteration, but a strong flame leaves a white scar which allows us to observe and measure the surface movement. Above our summit the heavenly continent is turning westward at 7¾ parasangs per hour. The play of prismatic colours across the surface is an effect of the sunlight, and quite unrelated to the real movement of the heavenly sphere, which is regular, continuous, and takes 27⅓ days to turn around the earthly sphere. In other words, it rotates with the moon.
“You have asked me questions about the heavenly continent: how thick, if pierceable etcetera. At least one more test is needed before I can answer accurately, but I can now tell you what is imaginable and what is likely.
“Classical astronomy would regard the heavenly firmament as the inner surface of a glassy shell carrying the moon. But a rigid shell would be shattered by the speed of its rotation and our air would not stop a liquid shell falling to the earth below. The classical model only holds good if the sky is made of transparent vapour, at once lighter than air and as dense as molten metal. Such a vapour is impossible.
“So let us imagine there is a dense, transparent fluid filling the entire universe. Our earth occupies a bubble of air in this fluid, a bubble at the centre of a whirlpool. The heavenly bodies are floating round us in different currents at different speeds, the nearest current carrying the moon. This idea is both attractive and convincing: until we remember that the light of the farthest and steadiest stars would be reaching us through fluid moving in different speeds and directions. This would give the highest heavens a warped and shifting aspect they do not possess.
“I offer you a third model. You perhaps know that all water has a skin protecting it from air. This skin is invisible to the human eye, impalpable to human touch, yet tough enough for small insects to hang from, walk across, and build upon. Imagine, then, that there is a light vapour which lies upon air as air lies upon water, and reacts with air to create a tense surface, perhaps only a few atoms thick. This surface has properties which human insects cannot understand before they have sampled the vapour on the far side, but it moves with the moon because the moon pulls it along as it pulls the oceans of the world below. The greater speed is explained by the absence of shores and a solid bottom.
“This is the likeliest model of the world we occupy, and I ask leave to test it by the following means.
“Only flame impresses the heavenly surface, so let us build in our summit a furnace with a ring of burners, and let us direct against the sky a circle of flame five feet in diameter. If this does not cut a hole into the upper universe let us keep the furnace burning for a lunar month of 28 days. This should engrave a fault-line round the inside of the cosmic eggshell, perhaps splitting it open long enough for us to grab a sample of what lies beyond.
“This test should endanger nobody, unless, perhaps, those beside the burners, foremost of whom will be myself. The sky will suffer no great injury. Flames mark it, yes, but since the start of the world it has been pierced from above, every night, by jagged meteorites of white-hot stone and iron. The heavenly surface would be scarred all over if these had done lasting damage. You can authorize my test in the knowledge that the natural forces maintaining the sky will start repairing it as soon as we relax our efforts. Man can no more destroy the sky than he can destroy the ocean.”