e dense timber where the wind
was broken. From their starting-point they walked to the brook, finding
nothing to enlighten them. They then retraced their steps, walking along
the windward edge of the fire. Yet they found nothing to show them how or
where the fire originated.

"Evidently the flames have eaten their way some distance to windward of
the point of origin," said the forester. "We shall have to look within the
burned area."

As he started to cross the black strip, the forester continued: "Perhaps I
had better go through the burned strip alone. I want things disturbed as
little as possible, and three will stir up the ashes a good deal more than
one. You keep looking along the edge, and I'll search among the ashes."

"Is there anything in particular we are to look for?" asked Charley. "Is
there any special way to distinguish the starting-point of the fire?"

"If this blaze started at a camper's fire, there ought to be some trace of
that fire discoverable. If it began with a lighted match, the stem of that
match might not be entirely consumed. If blazing paper created the fire,
there may be a scrap of paper left unburned. And even the ashes might show
that paper had been burned. That's why I don't want the leaves disturbed
any more than we can help. We shall quite likely find our clue, if we find
it at all, in the ashes themselves."

The forester started slowly across the valley.

"I don't see where he has anything on us as observers," said Lew. "If our
drill at Camp Brady didn't make competent observers of us, I don't know
what it did do. Captain Hardy drilled us and drilled us in noticing even
the most minute things. Let's go along the line again and look more
carefully. We've got a better idea now of what we're looking for."

They started once more along the edge of the black belt. The forester was
walking well within the burned area. The two boys centred their attention
on the strip between the forester's tracks and the edge of the black area.
This was a strip roughly fifty to seventy-five feet wide. Practically
everything was blackened in this area. A piece of unburned paper would
have shown with startling distinctness. But there were no pieces to show.
The forester crossed the black belt from brook to mountain, and the boys
kept pace with him for a little. Then Lew turned back in order to listen
in, while Charley went on with the forester. For a long time the two
searched among the leaves, but found n