It was the material with which Jack had dried his letter.
"Anybody got a mirror ?" asked Rob.

"This blotter may help some if we can read what's on it." "I've got a pocket one," said Andy Bowles, who was somewhat particular about his person and always carried a small toilet case.
"That will do; let's have it." Rob seized the bit of looking glass and held the blotter to it.
"Just as I thought," he exclaimed a minute later, with a cry of triumph.

"It's Jack Curtiss' writing, though he has tried to disguise it, and they've got Joe hidden somewhere.

Look here, they want $200 for his return." "Yes, but what good does it do us to know that," objected Merritt, when the sensation this announcement caused had subsided.

"They evidently had him here overnight and then deserted the camp for fear we'd pick up their trail.