Dune

In the manner of a teacher answering a child who has asked the sum of 2 plus 2, Kynes told them: "From three hundred to five hundred years."

A lesser folk might have howled in dismay. But the Fremen had learned patience from men with whips. It was a bit longer than they had anticipated, but they all could see that the blessed day was coming. They tightened their sashes and went back to work. Somehow, the disappointment made the prospect of paradise more real.

The concern on Arrakis was not with water, but with moisture. Pets were almost unknown, stock animals rare. Some smugglers employed the domesticated desert ass, the kulon, but the water price was high even when the beasts were fitted with modified stillsuits.

Kynes thought of installing reduction plants to recover water from the hydrogen and oxygen locked in native rock, but the energy-cost factor was far too high. The polar caps (disregarding the false sense of water security they gave the pyons) held far too small an amount for his project . . . and he already suspected where the water had to be. There was that consistent increase of moisture at median altitudes, and in certain winds. There was that primary clue in the air balance—23 per cent oxygen, 75.4 per cent nitrogen and .023 per cent carbon dioxide—with the trace gases taking up the rest.

There was a rare native root plant that grew above the 2,500 meter level in the northern temperate zone. A tuber two meters long yielded half a liter of water. And there were the terraform desert plants: the tougher ones showed signs of thriving if planted in depressions lined with dew precipitators.

Then Kynes saw the salt pan.

His 'thopter, flying between stations far out on the bled, was blown off course by a storm. When the storm passed, there was the pan—a giant oval depression some three hundred kilometers on the long axis—a glaring white surprise in the open desert. Kynes landed, tasted the pan's storm-cleaned surface.

Salt.

Now, he was certain.

There'd been open water on Arrakis—once. He began reexamining the evidence of the dry wells where trickles of water had appeared and vanished, never to return.

Kynes set his newly trained Fremen limnologists to work: their chief clue, leathery scraps of matter sometimes found with the spice-mass after a blow. This had been ascribed to a fictional "sandtrout" in Fremen folk stories. As facts grew into evidence, a creature emerged to explain these leathery scraps—a sandswimmer that blocked off water into fertile pockets within the porous lower strata below the 280° (absolute) line.

This "water-stealer" died by the millions in each spice-blow. A five-degree change in temperature could kill it. The few survivors entered a semidormant cyst-hibernation to emerge in six years as small (about three meters long) sandworms. Of these, only a few avoided their larger brothers and pre-spice water pockets to emerge into maturity as the giant shai-hulud. (Water is poisonous to shai-hulud as the Fremen had long known from drowning the rare "stunted worm" of the Minor Erg to produce the awareness-spectrum narcotic they call Water of Life. The "stunted worm" is a primitive form of shai-hulud that reaches a length of only about nine meters.)

Now they had the circular relationship: little maker to pre-spice mass; little maker to shai-hulud; shai-hulud to scatter the spice upon which fed microscopic creatures called sand plankton; the sand plankton, food for shai-hulud, growing, burrowing, becoming little makers.

Kynes and his people turned their attention from these great relationships and focused now on micro-ecology. First, the climate: the sand surface often reached temperatures of 344° to 350° (absolute). A foot below ground it might be 55° cooler; a foot above ground, 25° cooler. Leaves or black shade could provide another 18° of cooling. Next, the nutrients: sand of Arrakis is mostly a product of worm digestion; dust (the truly omnipresent problem there) is produced by the constant surface creep, the "saltation" movement of sand. Coarse grains are found on the downwind sides of dunes. The windward side is packed smooth and hard. Old dunes are yellow (oxidized), young dunes are the color of the parent rock—usually gray.

Downwind sides of old dunes provided the first plantation areas. The Fremen aimed first for a cycle of poverty grass with peatlike hair cilia to intertwine, mat and fix the dunes by depriving the wind of its big weapon: movable grains.

Adaptive zones were laid out in the deep south far from Harkonnen watchers. The mutated poverty grasses were planted first along the downwind (slipface) of the chosen dunes that stood across the path of the prevailing westerlies. With the downwind face anchored, the windward face grew higher and higher and the grass was moved to keep pace. Giant sifs (long dunes with sinuous crest) of more than 1,500 meters height were produced this way.