e mails, not over the telephone, not by telegraph, and
yet he has done it."

"By wireless, perhaps?" suggested Mr. Czenki. It was the first time
he had spoken, and the detective took occasion then and there to stare
at him frankly.

"And not by wireless," he said at last. "He sends and receives
messages from the roof of his house in Thirty-seventh Street by
homing pigeons!"

"Some more fandastics, eh, Laadham?" Mr. Schultze taunted. "Some
more chimericals?"

"I demonstrate this much by the close watch I have kept of Mr. Wynne,"
the detective went on, there being no response to his questioning look
at Mr. Schultze. "One of my agents, stationed on the roof of the
house adjoining Mr. Wynne's" (it was the maid-servant next door) "has,
on at least one occasion, seen him remove a tissue-paper strip from a
carrier pigeon's leg and read what was written on it, after which he
kissed it, gentlemen, kissed it; then he destroyed it. What did it
mean? It means that that particular message was from the girl to whom
he transferred the diamonds in the cab, and that he is madly in love
with her."

"Oh, dese wimmins! I dell you!" commented Mr. Schultze.

There was a little pause, then Mr. Birnes continued impressively:

"This correspondence is of no consequence in itself, of course. But
it gives us this: Carrier pigeons will only fly home, so if Mr.
Wynne received a message by pigeon it means that at some time, within
a week say, he has shipped that pigeon and perhaps others from the
house in Thirty-seventh Street to that person who sent him the
message. If he sends messages to that person it means that he has
received a pigeon or pigeons from that person within a week. And how
were these pigeons shipped? In all probability, by express. So,
gentlemen, you see there ought to be a record in the express offices,
which would give us the home town, even the name and address, of the
person who now has the diamonds in his or her keeping. Is that clear
to all of you?"

"It is perfectly clear," commented Mr. Laadham admiringly, while the
German nodded his head in approval.

"And that is the clew we are working on at the moment," the detective
added. "Three of my men are now searching the records of all the
express companies in the city--and there are a great many--for the
pigeon shipments. If, as seems probable, this clew develops, it may
be that we can place our hands on the diamonds within a few days."

"I don'd d'