CHAPTER X
The Island-Surrounded Island
Early next morning the Catwhisker left its mooring under the tamarack and started on the new search for the "Canadian Crusoe's" island.
Guided by the "mathematical chart" prepared with the directions given by the radio-compass amateur, the crew of the motor boat had little difficulty in finding the approximate location of the island prison; but when arrived there, they realized that considerable work was still 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," Cub proposed.
The run was made, with Cub in charge of the wheel and engine controls.
They circumnavigated the island with unsatisfactory result.
"That settles it," Bud declared. "If San Salvador had been like that,
Columbus would have made his first landing somewhere else!"
"Robinson Crusoe would never have found any footprints in the sand there," Hal declared.
"Yes, we'll give it up for the time being," Mr. Perry declared. "We won't try to scale any perpendicular banks, fifteen or twenty feet high, at least, not to begin with."
"I tell you what we ought to do," Hal volunteered next. "Let's accept this island as the center of probability."
"What in thunder is that?" Cub demanded.
"That's a good one on you, son," laughed the latter's father. "I thought you were the highbrow of your bunch; but here's our subtle Tee-hee putting a bit of clever phraseology over on you."
"Oh, I know what he means," Cub rejoined with a panicky haste to recover lost prestige. "I was just giving him a dig. He's forever giving me one, whenever I come along with anything of that kind."
"It indicates that his mind is maturing rapidly," said Mr. Perry. "All right, Hal, we'll accept this island as a center of probability—what next?"
"Why, let's cruise around about half a mile in all directions and pick out those islands that look as if they might have concealed a prisoner from view of passing boats."
"That's a good suggestion," said Mr. Perry. "Bob, start the boat again."
The inspection required about an hour, at the end of which they compared notes and found that their island inventory disclosed the following conditions:
Three possible places of concealment for the "Canadian Crusoe" had been discovered. Two were small islands a short distance from each other in a region of shallows and more or less hidden by rows of long slim islands. No boat of greater draught than a canoe could make its way through the intervening passages. In other words, these islands were virtually isolated from all river traffic. The other possible place of concealment was an island about five acres in extent, completely hemmed in by a group of other islands, which were so overrun with rampant vegetation, including bushes and trees, as to conceal the inner isle from any but the most scrutinizing vision.
"That is the place we want to explore first," announced Mr. Perry as reference was made to this retreat in the check-up.
"I agree with you," Bud declared. "If the prisoner left any traces behind him at all, we're likely to find them on that island in there."
"Is there any way we can get in?" Hal inquired. "Too bad we haven't a small rowboat or canoe with us."
"We'll investigate and see what we can find in the way of a water passage into the interior," Mr. Perry announced.
"That means a little more circumnavigating," Bud inferred.
"Right you are," said Cub. "Me to the pilot house again."
Accordingly he resumed his position at the wheel and the boat was put in motion again. His father followed him and cautioned him against too much speed in such places.
Slowly the Catwhisker crept around the island-surrounded island until they discovered a passage somewhat wider and apparently deeper than others they had seen thus far in the outer rim.
"It looks as if we might get through there," suggested Hal. He and Bud had followed into the pilot house soon after Cub and his father repaired to that place.
"It does look a little that way," replied Mr. Perry.
"We might creep in there slowly, and if we find the passage obstructed so as to block our way, we could back out," Hal continued.
"We have some long fender poles," Cub amended. "We could feel our way with them and probably keep out of serious trouble."
"All right, let's make the attempt," said Mr. Perry. "I'd very much like to get in there with this boat."
Cub started the engine and the Catwhisker began slowly to nose its way through the passage. In a few minutes the little craft was alongside a ledge of rock that projected as a sort of forehead from the top of a perpendicular short front, and the pilot brought her to a full stop.