"Let me see it. May I?"
He handed it to her. She could make nothing of it, so together they puzzled over it. The sailor rubbed it with a mixture of kerosene and sand. Then figures and letters and a sort of diagram were revealed. At last they became decipherable. By exercising patient ingenuity some one had indented the metal with a sharp punch until the marks assumed this aspect (see cut, following page).
Iris was quick-witted. "It is a plan of the island," she cried.
"Also the latitude and the longitude."
"What does 'J.S.' mean?"
"Probably the initials of a man's name; let us say John Smith, for instance."
"And the figures on the island, with the 'X' and the dot?"
"I cannot tell you at present," he said. "I take it that the line across the island signifies this gap or canyon, and the small intersecting line the cave. But 32 divided by 1, and an 'X' surmounted by a dot are cabalistic. They would cause even Sherlock Holmes to smoke at least two pipes. I have barely started one."
She ran to fetch a glowing stick to enable him to relight his pipe.