eep blue sky one dark spot where the lump of basalt
was speeding upon its way.

"Splendid!" cried the undaunted Challenger, rubbing his injured arm.
"A most thorough and satisfactory demonstration! I could not have
anticipated such a success. Within a week, gentlemen, I promise that a
second balloon will be prepared, and that you can count upon taking in
safety and comfort the first stage of our homeward journey." So far I
have written each of the foregoing events as it occurred. Now I am
rounding off my narrative from the old camp, where Zambo has waited so
long, with all our difficulties and dangers left like a dream behind us
upon the summit of those vast ruddy crags which tower above our heads.
We have descended in safety, though in a most unexpected fashion, and
all is well with us. In six weeks or two months we shall be in London,
and it is possible that this letter may not reach you much earlier than
we do ourselves. Already our hearts yearn and our spirits fly towards
the great mother city which holds so much that is dear to us.

It was on the very evening of our perilous adventure with Challenger's
home-made balloon that the change came in our fortunes. I have said
that the one person from whom we had had some sign of sympathy in our
attempts to get away was the young chief whom we had rescued. He alone
had no desire to hold us against our will in a strange land. He had
told us as much by his expressive language of signs. That evening,
after dusk, he came down to our little camp, handed me (for some reason
he had always shown his attentions to me, perhaps because I was the one
who was nearest his age) a small roll of the bark of a tree, and then
pointing solemnly up at the row of caves above him, he had put his
finger to his lips as a sign of secrecy and had stolen back again to
his people.

I took the slip of bark to the firelight and we examined it together.
It was about a foot square, and on the inner side there was a singular
arrangement of lines, which I here reproduce:

They were neatly done in charcoal upon the white surface, and looked to
me at first sight like some sort of rough musical score.

"Whatever it is, I can swear that it is of importance to us," said I.
"I could read that on his face as he gave it."

"Unless we have come upon a primitive practical joker," Summerlee
suggested, "which I should think would be one of the most elementary
developments of man."

"It is clearly som