the surface. Then, while she went to get lunch ready, Redgrave took
the pieces of rock and the bag of dust into the laboratory which opened
out of the main engine-room and analysed them. When he came out about an
hour later he saw Murgatroyd going through his beloved engines with an
oil-can and a piece of common cotton-waste which had come from a faraway
Yorkshire mill.

"Andrew," he said, "should you be surprised if I told you that that moon
we've just left seems to be mostly made of a spongy sort of alloy of
gold and silver?"

"My lord," said the old engineer, straightening himself up and looking
at him with eyes in which this announcement had not seemed to kindle a
spark of interest, "after what I have seen so far there's nothing
that'll surprise me unless it be that the grace of God allows us to get
back safely."

"Amen, Andrew, that's well said," replied Redgrave, and then he went
back to the saloon and Murgatroyd went on with his oiling.

When he told her ladyship of his discovery she just looked up from the
table she was laying and said:

"Oh, indeed! Well, I'm very glad that it's five or six hundred million
miles from the Earth. A dead world bigger than the Moon, and made of
gold and silver sponge, wouldn't be a nice thing to have too near the
Earth. There's trouble enough about that sort of thing at home as it is.
Still, it'll be a nice addition to the museum, and if you'll put it away
and go and wash your hands lunch will be ready."

When they got back to the deck-chamber Calisto was already a half moon
in the upper sky nearly five hundred thousand miles away, and the full
orb of Ganymede, shining with a pale golden light, lay outspread beneath
them. A thin, bluish-grey arc of the giant planet overarched its western
edge.

"I think we shall find something like a world here," said her ladyship,
when she had taken her first look through her telescope; "there's an
atmosphere and what look like thin clouds. Continents and oceans too, or
something like them, and what is that light shining up between the
breaks? Isn't it something like our Aurora?"

"It might be," replied Redgrave, turning his own telescope towards the
northern pole of Ganymede, "though I never heard of a satellite having
an aurora. Perhaps it's the Sun shining on the ice."

As the _Astronef_ fell towards the surface of Ganymede she crossed his
northern pole, and the nearer they got the plainer it became that a
light very like the terrest