example to do at school, and finally after
working at it a long time you have to confess you can't do it--does that
mean it's a mystery and you are mystified?"

This was a poser for the boys. They had never looked at a subject of this
kind on any such light.

"Cub, you're the highbrow of our bunch," said Hal after some moments of
puzzled silence.

"Oh, get away with that stuff," Cub protested, but, somehow, a faint
glimmer of satisfaction at the "compliment" shone in his countenance.

"No, I won't, either," Hal insisted. "It's true. This thing is too much
for Bud and me. You've got to settle it for us."

Cub "swelled up" a little with importance at this admission. He was
sitting in a camp chair with his feet resting on the taffrail, it being
a habit of his to rest his feet on something higher than his head, if
possible, whenever seated. Now, however, there seemed to be a demand
for superior head-work, so he lowered his feet, straightened up his
back, and said:

"Well."--speaking slowly--"I don't want to get in bad with my father by
trying to prove I know more than he does, but my argument would be that
all of life is not arithmetic."

"Good!" exclaimed Hal, eager to defend his belief in things mysterious,
and Bud signified his approval in similar manner.

"Yes, that isn't bad at all," admitted Mr. Perry, glad to have stimulated
his son's mind into action. "But if we can't explain this affair with
mathematics, maybe we can explain it by some other element of human
education."

"What, for instance?" asked Cub. "Not by readin', 'ritin', or
'rithmetic."

"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 wo