"No, we'll exclude the three R's for the present, although all of them
may figure in our work before it is finished."

"Well," mused Cub; "the others are history, geography, spelling--"

"Why didn't you stop with geography?" asked his father.

"Geography!" exclaimed Bud. "How can you use that to explain a mystery?"

"It depends on whether geography is involved," Mr. Perry replied. "In
this case it seems to me that geography is a very important element. We
may have to know considerably more about the geography of the Thousand
Islands in order to solve this so-called mystery. Now, mind you, I don't
mean to say that we're going to get at the bottom of this affair, but I
do want to suggest that if it is to be solved by any systematic process,
the first elements to be employed in the process are a little geography
and a little arithmetic. With this in view, I would suggest that you get
busy with your wireless outfit and see what you can find out."

The three boys gazed curiously at Cub's father and then at one another in
a puzzled manner.

"Haven't I given you enough hint?" asked Mr. Perry. "I don't want to do
the work myself--in fact, I couldn't if I wished to, for I can't send a
wireless message; but if I could, I know exactly what I'd do."

"We might send a broadcast to all other amateurs and find out if any of
them can help us," Hal suggested.

"How could they help us?" asked Bud skeptically.