The Science of Control — Gulliver's Travels

Gulliver's tutor shows him how Laputa moves. The island is a four, and, a, half, mile disk of adamant and soil, drained by basins the king can starve of rain. At its heart a loadstone like a weaver's shuttle, turned on an axle, attracts and repels the earth below so the whole mass rises, falls, and glides obliquely across Balnibarbi, never beyond the monarch's dominions or four miles up. Astronomers who live in the cave beneath tend the stone and boast telescopes that catalog ten thousand stars and two Martian moons. Power follows the magnet. If a town rebels, refuses tribute, or splits into factions, the king first hovers the island to steal sun and rain until dearth and disease bite; he may drop great stones while roofs cave in.

If they remain obstinate, he can let the island fall on their heads. Ministers with estates below resist the last remedy because it would ruin them and make them odious. Even the king rarely crushes a city outright: tall rocks and spires might crack the adamant bottom, break the loadstone's hold, and send Laputa itself crashing down, so he descends gently out of tenderness that is mostly fear. Three years before Gulliver arrived, Lindalino rebelled. In days the citizens seized the governor, built four towers at the corners of their square city and on the central rock, mounted loadstones, and stockpiled fuel to burst the island's belly if magnets failed. When the king blocked the sun and threw stones, they sheltered in the towers and sent down bold demands, not petitions.

He lowered the island forty yards; it began to tilt and rush downward until experiment proved their magnets pulled the adamant base. The king granted their terms. A minister told Gulliver the citizens would have fixed the island in place and killed the royal household if it could not rise. By law the king, his two eldest sons, and the queen until past childbearing may never leave the sky. The science is dazzling; the purpose is obedience.