Among the castaways of Earthquake Island was a Mr. Barcoe Jenks and
a Professor Ralph Parker. Mr. Jenks was a strange man, and claimed
to have some valuable diamonds, which he said were made by a gang of
men hidden in a cave in the Rocky Mountains. Tom did not believe
that the diamonds were real, but Mr. Jenks soon proved that they
were.

He asked Tom to aid him in searching for the cave of the diamond
makers. Mr. Jenks had been there once--in fact, he had been offered
a partnership in the diamond-making business, but, after he had paid
his money, he had been drugged, and carried secretly from the cave
before he had a chance to note its location.

But he, together with Tom, Mr. Damon and the scientist Mr. Parker,
who correctly predicted the destruction of Earthquake Island, set
out in the RED CLOUD to find the diamond makers. They did find them,
after many hardships, and were captured by the gang. How Tom and his
friends escaped from the cave, after they had seen diamonds made by
a powerful lightning flash, and how they nearly lost their lives
from the destruction of Phantom Mountain, is fully set down in the
book.

Sufficient to say now, that, though they had a general idea of how
the precious stones were made, by the power of the lightning, the
young inventor and his friends were never quite able to accomplish
it, and the secret remained a secret. But they had secured some
diamonds as they rushed from the cave (Mr. Damon grabbing them up)
and these were divided among Tom and the others.

Just as they were ready to come home in the airship, our friends