rson above
them nor could he see them. When they reached the flooring of the big
bridge they were less than two hundred feet from where the unknown
person stood. He was leaning over the side of the structure, evidently
trying to find out what had become of them.

"Why, Dave, he--he--looks like you!" burst out the senator's son, as
both hurried in the direction of the unknown person.

"I do believe it's Ward Porton!" ejaculated our hero. He began to
quicken his pace. "Yes, I'm almost sure it's Porton," he added, a few
seconds later.

"If it's Porton what in the world tempted him to follow you to this
place?" queried Roger.

"I don't know. But I do know that I'm going to capture him if it is
possible to do so," answered Dave, with determination.

The two chums were still almost a hundred feet from the other person
when the latter glanced up suddenly and discovered them. He looked
them full in the face for just an instant, and then turned and began
to run away towards the opposite end of the long bridge.

"It's Porton, sure enough!" burst out Roger.

"Hi there, Porton! Stop!" cried Dave. "Stop, I tell you!"

"You go on back!" yelled Ward Porton, in an ugly voice. "Go on back, I
tell you! If you don't it will be the worse for you!" and he shook his
fist at the chums.

"You might as well stop," continued Dave, undaunted by the threat.
"You can't get away from us. If you try to jump off the unfinished end
of the bridge you'll break your neck."

"If you fellows don't go back I'll shoot," returned the fellow who
resembled Dave. "Stop right where you are! Don't dare to come a step
closer!"

"Oh, Dave! do you suppose he is armed?" questioned Roger, hastily and
in a low tone.

"Maybe he is. But I am going to keep on after him until he shows his
pistol," was the rapid reply. "You need not come if you don't want to.
I'm going to capture him and make him give up the Basswood fortune."

"If you are going after him, so am I," returned the senator's son,
sturdily. "Maybe it was only a bluff about shooting after all."

While running along the bridge Dave's eyes fell on a short steel bar
left there by one of the workmen. He stopped just long enough to pick
the bar up, and then went after Porton with all the speed at his
command.

It was a perilous chase, for in many places the flooring of the big
bridge was still missing and they had to leap from girder to girder of
the steel structure.

"Stop, I tell you!" yelled Wa