ill
before them, for they were in the midst of a veritable sea of islands,
varying in size from a few car-loads of stone and earth to several acres
in extent.

"Well, how are we goin' to begin?" asked Hal as Cub stopped the engine in
a pond-like expanse, surrounded by a more or less regular rim of islands.

"The first thing to do, I should say is to make the best possible
reckoning of our bearings and then try to fix the point of intersection
of those three lines indicated by the radio compasses," said Mr. Perry.

"That's right," Cub agreed. "We mustn't forget our mathematics."

"It seems to me that we ought to be able to pick this place on the
chart," Bud suggested.

"Yes, especially if we keep in mind the location of some other landmarks,
or watermarks, that we passed in the last half or three-quarters of an
hour in getting here," said Hal.

Cub produced the chart, and the study of locations and island
arrangements began. As indicated by expectations in the course of their
discussion, they were able to locate a few of the larger islands and with
these as bases for further reckoning, they at last picked out what seemed
to be the point of intersection of the three pencil lines on the chart.
This necessitated a little more cruising about, but within an hour after
their first stop they completed their reckoning.

"There's the island that seems to come nearest to the intersection,"
said Mr. Perry, pointing toward an abrupt elevation, a hundred yards
long and half as wide and covered with bushes and a few small trees;
"but it doesn't seem to answer the description very well. No other
islands near it."

"I don't see how anybody could be marooned on that place with boats
passing back and forth near it every hour of the day," Hal commented
skeptically.

"Neither do I," Bud agreed.

"Well, let's do our work thoroughly anyway," Mr. Perry suggested.

"Shall we go ashore and look that place over?" asked Hal.

"Sure."

"But what do you expect to find?" Cub inquired.

"I don't expect to find anything. I had no expectation when I suggested
that you boys canvass the radio field for information to clear up what
you chose to call a mystery. I had no idea what might turn up as a result
of such canvass, but I know it was about the only thing for you to do to
start a move in the desired direction."

"And something sure did move," Hal remarked appreciatively.

"Well, let's run around this island and find a landing place,