t the 'phone, Mr. Drowan hung over the box
as though fascinated.

"It takes fire to set this stuff off, doesn't it?" he asked.

"No," Dick replied. "If it's nitroglycerine in that box,
a light, sharp blow might be enough to do the trick. At least,
that was about what Dr. Thornton said."

Dave came back with word that the police would send some one at
once.

"They asked me whom the stuff was addressed to," Dave continued,
"and I had to admit that I didn't know."

"It's addressed to Simon Tripps, to be called for. Identification
by letter herewith," read Dick Prescott, from the label.

"Yes; I have the letter," nodded Mr. Drowan. "It contains the
signature of the party who's to call for the box. That's all
the identification that's asked."

At this moment Officer Hemingway, in plain clothes, came in, followed
by a policeman in uniform.

Hemingway took a look at the stuff slowly oozing out of a corner
of the box.

"My bet is nitroglycerine---what the bank robbers call 'soup,'"
declared Hemingway, almost in a whisper. "All right; we'll take
it up to the station house. Then we'll send for Dr. Thornton,
who is the best chemist hereabouts. As soon as we get this stuff
to the station house I'll hustle back and hide against the coming
of Mr. Tripps. If he comes before I get back, jump on the fellow
and hold him for me, no matter what kind of a fight he puts up."

Dave gazed after the retreating figures of the policemen.

"Bright man, that Hemingway," he remarked. "If Tripps shows up,
we are to jump on him and nail him---no matter if he hauls out
two six-shooter and turns 'em on us"

"We can grab any one man, and hold him," returned Dick, confidently.
"All we've got to do is to get at him from all sides. See here,
Dave, if a fellow comes in and tells you he's Tripps, you repeat
the name as though you weren't sure. As soon as we hear the name,
Tom and I can jump on him from behind, and you can sail in in
front. Eh, Reade?"

"It sounds good," nodded Tom. "I'll take a chance on it, Dick,
with you to engineer the job."

In ten minutes Officer Hemingway was back. He stepped into a
cupboard close to the counter, prepared for the coming of Tripps.

Half an hour later the police station's officer in charge telephoned
that Dr. Thornton had carefully opened the box, and had declared
that it contained four pounds of nitroglycerine. Nor had Dr.
Thornton taken any chances of mistake. He had taken a minute