rdman. "Those tanks are full of compressed air at
rather high pressure--a couple of thousand pounds. Here's a
reduction-valve with an adiabatic expansion feature, to supply extra air
to your heat-suit. It will be pretty cold, expanding from so high a
pressure. Bring down the temperature a little more."

Bordman again felt humiliated. Chuka and Redfeather, because of their
races, were able to move about nine-tenths naked in the open air on this
planet, and they thrived. But he needed a special refrigerated costume
to endure the heat. More, they provided him with sunshades and
refrigerated air that they did not need for themselves. They were
thoughtful of him. He was as much out of his element, where they fitted
perfectly, as he would have been making a degree-of-completion survey on
an underwater project. He had to wear what was practically a diving suit
and use a special air supply to survive!

He choked down the irritation his own inadequacy produced.

"I suppose we can go now," he said as coldly as he could.

Aletha's cousin mounted the control-saddle--though it was no more than a
blanket--and Dr. Chuka mounted beside Bordman. The ground car got under
way. It headed for the mountains.

* * * * *

The smoothness of the rock was deceptive. The caterwheel car lurched
and bumped and swayed and rocked. It rolled and dipped and wallowed.
Nobody could have remained in a normal seat on such terrain, but Bordman
felt hopelessly undignified riding what amounted to a hobbyhorse. Under
the sunshade it was infuriatingly like a horse on a carousel. That there
were three of them together made it look even more foolish. He stared
about him, trying to take his mind from his own absurdity. His goggles
made the light endurable, but he felt ashamed.

"Those side-fins," said Chuka's deep voice pleasantly, "the bottom ones,
make things better for you. The shade overhead cuts off direct sunlight,
and they cut off the reflected glare. It would blister your skin even
if the sun never touched you directly."

Bordman did not answer. The caterwheel car went on. It came to a patch
of sand--tawny sand, heavily mineralized. There was a dune here. Not a
big one for Xosa II. It was no more than a hundred feet high. But they
went up its leeward, steeply slanting side. All the planet seemed to
tilt insanely as the caterwheels spun. They reached the dune's crest,
where it tended to curl over and break like a water-