And certainly Tom Swift had many things to do now. He hardly knew
at what to begin first, but now, since he was on the right road in
regard to his photo telephone, he would work at improving it.

And to this end he devoted himself, after he had sent out a
general alarm to the police of nearby towns, in regard to the
disappearance of Mr. Damon. The airship clue, he believed, as did
the police, would be a good one to work on.

For several days after this nothing of moment occurred. Mr. Damon
could not be located, and Tom's airship might still be sailing
above the clouds as far as getting any trace of it was concerned.

Meanwhile the young inventor, with the help of Ned, who was given
a leave of absence from the bank, worked hard to improve the photo
telephone.





CHAPTER XV

THE AIRSHIP CLUE


"Now Ned, we'll try again. I'm going to use a still stronger
current, and this is the most sensitive selenium plate I've turned
out yet. We'll see if we can't get a better likeness of you--one