d Tom, having seen one train of the dump
cars loaded, sat down to rest on an elevated ledge of rock, where he
had made a sort of easy chair for himself, with empty cement bags for
cushions.

The heat, his weariness and the monotonous clank-clank of a water pump
near by, and the equally monotonous thump of the lumps of rocks in the
cars made Tom drowsy. Almost before he knew it he was asleep.

What suddenly awakened him he could not tell. Perhaps it was some
influence on the brain cells, as when a vivid dream causes us to start
up from slumber, or it may have been a voice. For certainly Tom heard a
voice, he declared afterward.

As he roused up he found himself staring at the rocky wall of the
tunnel. And yet the wall seemed to have an opening in it and in the
opening, as if it were in the frame of a picture, appeared the face Tom
had seen at his library the day Job Titus called on him--the face of
Waddington!

Tom sat up so quickly that he hit his head sharply on a projecting rock
spur, and, for the moment he "saw stars." And with the appearance of
these twinkling points of light the face of Waddington seemed to fade
away, as might a vision in a dream.

"Bless my salt mackerel, as Mr. Damon would say!" cried Tom. "What have
I discovered?"

He rubbed his head where he had struck it, and then passed his hand
before his eyes, to make sure he was awake. But the vision, if vision
it was, had vanished, and he saw only the bare rock wall. However, the
echo of the voice remained in his ears, and, looking down toward the
tunnel floor Tom saw Serato, the Indian foreman.

"Were you speaking to me?" asked Tom, for the man understood and spoke
English fairly well.

"No, sar. I not know you there!" and the fore man seemed startled at
seeing Tom. Clearly he was in a fright.

"You were speaking!" insisted Tom.

"No, sar!" The man shook his head.

"To some one up there!" went on the young inventor, waving his hand
toward the spot where he had seen the face in the rock.

"Me speak to roof? No, sar!" Serato laughed.

Tom did not know what to believe.

"You hear me tell um lazy man to much hurry," the Indian went on. "Me
not know you sleep there, sar!"

"Oh, all right," Tom said, recollecting that he must keep up his
disguise. "Maybe I was dreaming."

"Yes, sar," and the foreman hurried on, with a backward glance over his
shoulder.

"Now was I dreaming or not?" thought Tom. "I'm going to have a look at
that place th