ned upside
down, in exactly this way. This is the place. It rested on this flat
stone. The skull was behind it on this upper shelf."

"And was there nothing else on the shelf?"

"Nothing whatever."

John stooped down and carefully examined the shelf. All followed his
motions. "Do you see that mark?" he said, pointing to a heavy scratch,
which was now plain. "That mark is associated with the skull, if not
with the message. I am unable at this time fully to decipher the marks
on the skull, but I have an idea of the meaning."

"I wonder if the scratch across that is in the same direction as the
arrow in the letter?" asked George.

"Unquestionably: let me see your glasses," and George unslung them as
John took them and gazed long in the direction of the line on the shelf.

He lowered the glasses and slowly shook his head. Something was forming
itself in his mind, this was evident. He walked around the ledge and
back again. Finally, he said: "I wish it were night, it might help to
solve the riddle."

"And why?" asked Harry.

"Those letters have reference to the star which follows."

"It seems to me to be a singular thing that anyone should leave this
here in the hope or expectation that it could be a guide for any one,"
remarked George.

"There is certainly one explanation of that," answered John. "It is
evident that the articles were placed there as a form of note to others,
and it is a sort of cryptic sign, intelligible only to those who have
the key. The fact that these signs are here denote several things, one
of which is that something important, such, for instance, as treasures,
or the location of hidden wealth, or the directions necessary to find
mining lodes, or even to point out the direction and distances of other
islands in the distance."

"But," said Harry, "the fact that we have found these things here looks
as though there were other parties besides Walter and that he was
associated with them in some sort of enterprise."

"Quite true; but I am not at all satisfied that the Walter note has
anything to do with the skull. In fact there is every evidence to me
that they are entirely disconnected with each other."

This announcement was the most surprising to Blakely, who now added a
few points of information. "I should have said that the skull was not
exposed as you now see it on the shelf. After I went up the side of the
hill, I returned and landed on the ledge, and then I noticed the skull
throug