laughter. Mrs. Layton found him as amusing as did the boys.

At last the lunch came to an end and Mr. Brandon professed himself ready
to talk shop.

He was enthusiastic over the radio set the boys showed him and declared
that he could see very little improvement to suggest.

"You surely have kept up with the march," he said admiringly. "You have
pretty nearly all the latest appliances, haven't you? Good work, boys.
Keep it up and you'll be experts in earnest."

"If we could only find some way to lengthen the life of our storage
batteries," said Bob, not without a pardonable touch of pride, "we
wouldn't have much to complain about. But that battery does puzzle us."

"Keep your battery filled with water and see if it doesn't last you
about twice as long," suggested the radio expert. "Don't add any acid to
your battery, for it's only the water that evaporates."

"Will that really do the trick?" asked Joe, wondering. "I don't just see
how----"

"It does just the same," Brandon interrupted confidently. "All you have
to do is to try it to find out. Don't use ordinary water though. It
needs to be distilled."

"That's a new one on me, all right," said Bob, adding gratefully: "But
we're obliged for the information. If distilled water will lengthen the
life of our battery, then distilled water it shall have."

"It seems queer," said Mr. Brandon reflectively, "how apparently simple
things will work immense improvement. Marconi, for instance, by merely
shortening his wave length, is discovering wonderful things. We cannot
even begin to calculate what marvelous things are in store for us when
we begin to send out radio waves of a few centimeters, perhaps less. We
have not yet explored the low wave lengths, and when we do I believe we
are in for some great surprises."

"Go on," said Joe, as he paused. "Tell us more about these low wave
lengths."

CHAPTER XIV

A DARING HOLDUP

Frank Brandon shook his head and smiled.

"I'm afraid I don't know much more to tell," he said. "As I have said,
what will happen when we materially decrease the wave length, is still
in the land of conjecture. But I tell you," he added, with sudden
enthusiasm, "I'm mighty glad to be living in this good old age. What we
have already seen accomplished is nothing to what we are going to see.
Why," he added, "some scientists, Steinmetz, for instance, are even
beginning to claim that ether isn't the real medium for the propagation
of radio