ny
more than the rest of you. It just occurred to me that the reason why
we couldn't find Higginbotham links up with the reason why his
airplane is missing. Higginbotham flew away in it, while that plugugly
who damaged our airplane and whom Bob couldn't locate worked the radio
for him."

"You mean he had the nerve to come back here while we were up at the
house? And that his man calmly walked into the radio plant and
operated it for him? Oh, say." Bob was contemptuous.

"Why not?" said Frank coolly. "What was to stop him? The airplane
makes no noise, and it would be the easiest matter in the world for
Higginbotham thus to make his escape."

CHAPTER XIX

WARNED!

Frank's surmise was communicated to Captain Folsom, and the latter at
once sent a radio message to the Custom House at New York, giving a
bare outline of the details of the raid and asking that a watch be
kept for Higginbotham. Custom House communicated with the New York
Police Department, and a guard was set at the bridges and ferries
leading from Long Island to Manhattan.

Several days elapsed, however, with Higginbotham still uncaught.
Meanwhile the next day after that eventful night, the radio-controlled
plane was found floating in the waters of Great South Bay, so near the
shore as to make it practically impossible Higginbotham had been
drowned but, on the contrary, to give rise to the belief that he had
made his way ashore. A fisherman made the discovery.

It was some twenty-five miles as the crow flies from the Brownell
place to the point where the airplane came down. That, Jack
estimated, when told of the discovery, probably was the limit of the
radio plant's radius of control. Higginbotham, therefore, had not
descended until compelled to do so.

All this, however, did not come until later. Meanwhile, after saying
farewell to the two officers, the boys returned afoot to their homes
with the understanding on Jack's part that Captain Folsom, the main
portion of whose wardrobe still was at his house, would return later.
On arrival, Jack learned that Tom Barnum already had explained the
reason for his absence to the housekeeper and, after telling her
Captain Folsom should be shown to his room on arrival, turned in and
went instantly to sleep.

As for Bob and Frank, only the servants as yet were astir at the
Temple home. And the boys, after stating only that they had been
routed out by a fire at the airplane hangar, went instantly to bed.