He went back to his work. And it definitely seemed to be as purposeless as any man's work could possibly be. Down-grade from the now thoroughly deserted area in which ship-fuel tanks had leaked--quite far down-grade--he had commandeered all the refrigeration equipment in the warehouses. Since refrigeration was necessary for fuel-storage, there was a great deal. He had planted iron pipe in the soil, and circulated refrigerant in it, and presently there was a wall of solidly frozen earth which was shaped like a shallow U. It was a coffer-dam. In the curved part of that U he'd siphoned out a lake. A peristaltic pump ran sea water from the island's lee out upon the ground--where it instantly turned to mud--and another peristaltic pump sucked the mud up again and delivered it down-grade beyond the line of freezing-pipes. It was in fact a system of hydraulic dredging such as is normally performed in rivers and harbors. But when topsoil is merely former abyssal mud it is an excellent way to move dirt. Also, it does not require anybody to strike blows into soil which may be explosive when one has gotten down near bedrock, and in particular there are no clanking machines. But it was hair-raising. In one day, though, he had a sizable lake pumped out. And he pumped it out to emptiness, painstakingly smelling the water as it went down to a greater depth below the previous ground surface. At the end of the day he shivered and ordered pumping ended for the time. But then he had the brine-pipe laid around a great circuit, to the Headquarters ground which was upgrade from the now-deserted square mile or so in which the fuel tanks lay deep in the soil. And here, also, he performed excavation without the sound of hammer, shovel, or pick. He thrust pipes into the ground, and they had nozzles at the end which threw part of the water backward. So that when sea water poured into them it thrust them deeper into the ground by the backward jet action. Again the fact that the soil was abyssal mud made it possible. The nozzles floated up much grayish mud, but they bored ahead down to bedrock, and there they lay flat and tunneled to one side and the other--the tunnels they made being full of water at all times. From those tunnels, as they extended, an astonishing amount of sea water seeped out into the soil near bedrock. But it was sea water. It was heavily mineralized. And it is a peculiarity of sea water that it is an electrolyte, and it is a property of electrolytes that they coagulate colloids, and rather definitely discourage the suspension of small solid particles which are on the borderline of being colloids. In fact, the water of the ocean of Canna III turned the ground-soil into good, honest mud which did not feel at all soapy, and through which it percolated with a surprising readiness. Young Barnes eagerly supervised this part of the operation, once it was begun. He shamed the Survey personnel assigned to him into perhaps excessive self-confidence.