"You never can tell. Someone may have borrowed it without his knowledge. You'd better go a bit slow, Tom."
"Well, maybe I had. But it's a clew, anyhow."
Ned agreed to this.
"And all I've got to do is to find out who was in the coat when it was riding about in my airship," went on Tom.
"Yes," said Ned, "and then maybe you'll have some clew to the disappearance of Mr. Damon."
"Right you are! Come on, let's get busy!"
"As if we hadn't been busy all the while!" laughed Ned. "I'll lose my place at the bank if I don't get back soon."
"Oh, stay a little longer--a few days," urged Tom. "I'm sure that something is going to happen soon. Anyhow my photo telephone is about perfected. But I've just thought of another improvement."
"What is it?"
"I'm going to arrange a sort of dictaphone, or phonograph, so I can get a permanent record of what a person says over the wire, as well as get a picture of him saying it. Then everything will be complete. This last won't be hard to do, as there are several machines on the market now, for preserving a record of telephone conversations. I'll make mine a bit different, though."