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," Bordman said. "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 Bordman. "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?" "Y-yes, sir. I'll try." "If we had soil-coagulants enough," said Bordman, "we could handle that damned upside-down swamp the civilians have so carefully made here. But we haven't got it! The freshened sea-water they've been irrigating with is practically mineral-free! I want to know how much mineral content in the water would keep the swamp-mud from acting like wet soap. It's entirely possible that we'd have to make the soil too salty to grow anything, in order to anchor it. But I want to know!" Barnes said uncomfortably: "Wouldn't you--wouldn't you have to put the minerals in irrigation-water to get them down to the swamp?" Bordman grinned, surprisingly. "You've got promise, Barnes! Yes. I would. And it would increase the rate of slide before it stopped it. Which could be another problem. But it was good work to think of it! When we get back to Headquarters, you commandeer a laboratory and make those measurements for me." "Yes, sir," said Barnes. "We'll start back now," said Bordman. The recreation-boat obediently turned. It went out to sea until the water flowing past its hull was crystal-clear. And Bordman seemed to relax. On the way they passed more small boats. Many of them were gardeners' boats, from which men dived with diving-masks to tend or harvest the cultivated garden-patches not too far down. But many were pleasure-boats, from double-hulled sailing craft intended purely for sport, to sturdy, though small, cabin cruisers which could venture far out to sea, or even around to the windward of the island for sport-fishing. All the pleasure-craft were crowded--there were usually some children--and it was noticeable that on each one there were always some faces turned toward the shore.