"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: -. ... -. ... -. ... "N S," Joe jotted down on the sheet before him. "A ship at sea calling Newport News," Lieutenant Mackinson informed the other two, who waited impatiently for Joe to begin recording the message. Newport News acknowledged the call, and then the vessel's wireless continued: .--- .- ... .--. . .-. And Joe, transcribing, wrote: "JASPER." Following this came: -.. . - .- .. .-.. The other boys looked on in chagrin, while Lieutenant Mackinson's countenance took on an amused smile, as Joe wrote down the word "DETAIL," and then nothing else but the initials "N. N.," which ended the message.