is true. The bombs, of course, are controlled by radio, and
therefore may be attached to the outer wall of your vessel. We shall be
glad to do these small things for you."

The heaters of the _Forlorn Hope_ were shut off, and as soon as the
outer shell had cooled to Titanian temperature, a corps of mechanics set
to work. A machine very like a concrete mixer was rolled up beside the
steel vessel, and into its capacious maw were dumped boxes and barrels
of dry ingredients and many cans of sparkling liquid. The resultant
paste was pumped upon the steel plating in a sluggish, viscid stream,
which spread out into a thick and uniform coating beneath the flying
rollers of the skilled Titanian workmen. As it hardened, the paste
smoothed magically into the perfect mirror which covered the
space-vessels of the satellite; and a full dozen of the mirror explosive
bombs of this strange people were hung in the racks already provided.

"Once again I must caution you concerning those torpedoes," Barkovis
warned Stevens. "If you use them all, very well, but do not try to take
even one of them into any region where it is very hot, for it will
explode and demolish your vessel. If you do not use them, destroy them
before you descend into the hot atmosphere of Ganymede. The mirror will
volatilize harmlessly at the temperature of melting mercury, but the
torpedoes must be destroyed. Once more, Tellurians, we thank you for
what you have done, and wish you well."

"Thanks a lot for _your_ help--we still owe you something," replied
Stevens. "If either of your power-plants go sour on you again, or if
you need any more built, be sure to let us know--you can come close
enough to the inner planets now on your own beam to talk to us on the
ultra-communicator. We'll be glad to help you any way we can--and we may
call on you for help again. Goodbye, Barkovis--goodbye, all Titania!"

He made his way through the bitterly cold shop into the control-room of
their lifeboat, and while he was divesting himself of his heavy suit,
Nadia lifted the _Forlorn Hope_ into the blue-green sky of Titan,
accompanied by an escort of the mirrored globes. Well clear of the
atmosphere of the satellite, the terrestrial cruiser shot forward at
normal acceleration, while the Titanian vessels halted and wove a
pattern of blue and golden rays in salute to the departing guests.

"Well, Nadia, we're off--on a long trek, too."

"Said Wun Long Hop, the Chinese pee-lo," Nadia a