omatic
recording apparatus--in fact, every detail connected with the intricate
mechanism of an up-to-date wireless.

"There was a time," explained Lieutenant Mackinson, "when the sending of
a message almost deafened the sender. It was like being in the midst of
a machine-gun assault. But recent improvements have eliminated that. You
may see for yourselves."

And the lieutenant tapped off the _Everett's_ own signal call with
little more sound than is made by the sending of a message with the
ordinary telegraph instrument.

"We have a sending and receiving radius of from five hundred to eight
hundred miles," Lieutenant Mackinson continued. "Of course, it doesn't
compare with the great wireless station at Radio, Virginia, one of the
largest in the world, where one tower is six hundred feet high and the
other four hundred and fifty feet in height, and each charged with two
hundred thousand volts, giving a radius of three thousand miles; but it
is sufficiently powerful for practically every purpose required at sea."

"Wasn't Marconi a wonderful man?" said Jerry in true admiration.

"Yes, he was; no doubt of that, and he still may contribute much to the
science, for he is not old yet," the young lieutenant answered. "But
still, full credit must be given where credit is due, and in that
respect it must be acknowledged that Marconi only assembled and
perfected to practicable purposes the discoveries and inventions made
before his time.

"Radio-telegraphy might be briefly traced in the names of Faraday,
Maxwell, Hertz--the discoverer of the Hertzian rays--Righi, Lodge and
Marconi. All of them contributed something to the evolvement of the
present highly efficient and dependable wireless. Marconi should, and
does, receive great credit; but the others, the pioneers, the real
discoverers, should not be forgotten or overlooked."

The lieutenant's words threw a new light on the history of the wireless
for the boys from Brighton, and they were anxious that the officer
should tell them more; but at that moment Lieutenant Mackinson caught
the faint recording of a distant wireless call for another station, far
down the Atlantic coast.

"Here," he said hastily, turning to Joe, who was nearest him, "see if
you can catch this message."

He slipped the receiving apparatus over Joe's head, and tightened up the
ear-pieces, then pushed toward him a pad and pencil.

Into Joe's ears came the faint but distinct sounds of a distant call