nd; vanished beneath
them. More fields and roads. Everywhere there were yellows and reds
and the silver sheen of the roads. No green save that of the darkening
sky and the waters of the streams and ponds. It was a most inviting
panorama.

Occasionally they passed a vessel of the air--strange flapping-winged
craft that soared and darted like huge birds. Once one of them
approached so closely they could see its occupants, seemingly a people
similar to the Venusians, small of stature and slender.

"How in time are we to find this city of golden domes?" Carr
ejaculated.

As if in answer to his question there came a startling command,
another of the mental messages.

"Halt!" it conveyed to their mind. "Continue not into our country
until we have communed with you."

Obediently Mado brought up the nose of the _Nomad_ and slowed her down
to a gradual stop. They hovered at an altitude of about four thousand
feet, both straining their ears as if listening for actual speech.

"It is well," continued the message. "Your thoughts are good. You come
from afar seeking the city of golden domes. Proceed now and a fleet of
our vessels will meet you and guide you to our city."

"Now wouldn't that jar you?" whispered Carr. "Just try to get away
with anything on this world."

Mado laughed as he started the generators of the propelling
energy. "I'd hate to have a wife of Europa," he commented. "No
sitting-up-with-sick-friend story could get by with her!"

CHAPTER V

_The City of Golden Domes_

With the _Nomad_ cruising slowly over the surface of the peaceful
satellite, Mado sampled the atmosphere through a tube which was
provided for that purpose. The pressure was low, as they had expected;
about twenty inches of mercury in the altitude at which they drifted.
But the oxygen content was fairly high and the impurities negligible.
A strange element was somewhat in evidence, though Mado's analysis
showed this to be present in but minute quantity. They opened the
ports and drew their first breath of the atmosphere of Europa.

"Good air, Carr." Mado was sniffing at one of the ports. "A bit rare
for you, but I think you'll get along with it. Temperature of
forty-five degrees. That's not so bad. The strangest thing is the
gravity. This body isn't much more than two thousand miles in
diameter, yet its gravity is about the same as on Venus--seven eighths
of that of Terra. Must have a huge nickel-iron core."

"Yes. It'll be a cinch