"Now we believe he has joined forces hereabout with ancient enemies of the Federal officers. At least, there is a strange aeroplane reported from both sides of the border, and some fine gems have appeared in the hands of certain suspected dealers in Maine, and as far south as Boston and Providence.

"Bainbridge is known to be a desperate man. Look out for him, Professor. If you are hailed by another machine, better keep away from it," and the secret service agent laughed. "Had I been in your place I would not have halted on this occasion. You certainly can outsail any airship I have ever seen operated."

Mr. Ford seemed quite satisfied that our friends were law-abiding and he ascended to his waiting craft in a few moments; and the Snowbird started onward again through the starlight.

But the warning of the special agent had impressed the boys as well as t. . . Read More