elt the effect of it; it
made his head light and dizzy, and the smoke with which it was laden
brought back the choking sensation into his throat. He knew that he
must go farther in. He rose and went slowly along the heading, over
his accustomed route, until he reached a bench by a door that opened
into the air-way. Here he sat down again. He was tired and was
breathing heavily. A little exertion seemed to exhaust him so. He
could not quite understand it. He remembered when he had run all the
way from the plane to the north chambers with only a quickening of the
breath as the result. He was not familiar with the action of vitiated
air upon the system.

Jasper had followed him; so closely indeed that the beast's nose had
often touched the boy's shoulder as they walked.

Ralph's lamp seemed to weigh heavily on his head, and he unfastened it
from his cap and placed it on the bench beside him.

Then he fell to thinking again. He thought how anxious Bachelor Billy
would be about him, and how he would make every effort to accomplish
his rescue. He hoped that his Uncle Billy would be the first one to
reach him when the way was opened; that would be very pleasant for
them both.

Mrs. Burnham would be anxious about him too. He knew that she would;
she had been very kind to him of late, very kind indeed, and she came
often to see him.

Then the memory of Robert Burnham came back to him. He thought of the
way he looked and talked, of his kind manner and his gentle words. He
remembered how, long ago, he had resolved to strive toward the perfect
manhood exemplified in this man's life. He wondered if he had done the
best he could. The scenes and incidents of the day on which this good
man died recurred to him.

Why, it was at this very door that the little rescuing party had
turned off to go up into the easterly tier of chambers. Ralph had not
been up there since. He had often thought to go over again the route
taken on that day, but he had never found the time to do so. He had
time enough at his disposal now, however; why not make the trip up
there? it would be better than sitting here in idleness to wait for
some sign of rescue.

He arose and opened the door.

The mule made as if to follow him.

"You stay here, Jasper," he said, "I won't be gone long."

He shut the door in the animal's face and started off up the
side-heading. There had not been much travel on this road during the
last year. Most of the chambers in thi