The flow-away of the deeper soil made a greater, more cavernous hollow beneath the surface. It began to collapse. The house teetered. It fell. It smashed. More soil dropped down, and more, and more.
Presently there was a depression, a sort of valley leading inland away from the sea, in what had been a rampart of green at the water's edge. It was still green, but through the glasses Hardwick could see that trees had fallen, and a white-painted fence was splintered. And there was still movement.
The movement slowed and slowed, but it was not possible to say when it stopped. In reality, it did not stop. The island's soil was still flowing into the ocean.
Barnes drew a deep breath.
"I ... thought that was it, sir," he said shakily. "I mean ... that the whole island would start sliding."
"The ground's a bit more water-soaked down here," Hardwick said briefly. "Inland the bottom-soil's not nearly as fluid as here. But I'd hate to have a really heavy rainfall right now!"
Barnes' mind jerked back to the Sector Chief's office.
"The drumming would set off the ship-fuel?"
"Among other things," said Hardwick. "Yes." Then he said abruptly: "How good are you at precision measurements? I've messed around on swamp planets. I know a bit too much about what I ought to find, which is not good for accuracy. Can you take these bottles and measure the rate of sedimentation and plot it against salinity?"