they think they're justified in doing anything to get him back to
the Siberian mines. And once the Russian government sets out to do a
thing it generally does it--I'll give 'em credit for that."

"But how do you suppose they know you're going to Russia?"

"Say, those fellows have ways of getting information you and I would
never dream of. Why, didn't you read the other day how some fellow who
was supposed to be one of the worst Anarchists ever, high up in making
bombs, plotting, and all that sort of thing--turned out to be a police
spy? They get their information that way. I shouldn't be surprised but
what some of the very people whom Mr. Petrofsky thinks are his friends
are spies, and they send word to headquarters of every move he makes."

"Why don't you warn him?"

"He knows it as well as I do. The trouble is you can't tell who the
spies are until it's too late. I'm glad I'm not mixed up in that sort
of thing. If I can get to Siberia, help Mr. Petrofsky rescue his
brother, and get hold of some of that platinum I'll be satisfied. Then
I won't go back to the land of the Czar, once I get away from there."

"That's right. Well, let's go back and work on the glider."

"And we'll have Eradicate patrolling about the shop to make sure we're
not spied on again."

"By golly! Ef I sees any oh 'em, I suah will pinch 'em!" cried the
colored man, as he clicked the pliers.

But there was no further disturbance that night, and, when Tom and Ned
ceased work, they had made good progress toward finishing the air
glider.

The big airship was almost ready to be given a trial flight, with her
motors tuned up to give more power, and as soon as the Russian exile
had a little more definite information as to the possible whereabouts
of his brother, they could start.

In the days that followed Tom and his friends worked hard. The air
glider was made as nearly perfect as any machine is, and in a fairly
stiff gale, that blew up about a week later, Tom did some things in it
that made his friends open their eyes. The young inventor had it under
nearly as good control as he had his dirigible balloons or aeroplanes.

The big airship, too, was made ready for the long voyage, extra large
storage tanks for gasolene being built in, as it was doubtful if they
could get a supply in Siberia without arranging for it in advance, and
this they did not want to do. Besides there was the long ocean flight
to provide for.

"But if worst comes to wor