The callsign of "naval radio station at Arlington, Va." was NAA.
Bell Telephone News, December, 1915, page 14:

First  Public  Wireless  Demonstration

    Honoring their fellow-member, John J. Carty, chief engineer of the American Telephone and Telegraph Company, 300 members of the Lotos Club, of New York, on the night of November 27th listened to voices in the air and stood while "The Star Spangled Banner" was played to them at Arlington, Va., and transmitted by wireless telephone to their places at the tables.
    They exchanged greetings over 3,400 miles with the Bohemian Club of San Francisco over the long-distance telephone, and heard Mr. Carty talk to his wire chiefs across a continent. Every one of the 300 had the use of a receiver, and by wireless and also by the regular telephone service made the world a whispering gallery.
    This was the first large social function at which wireless telephony was a factor. Josephus Daniels, secretary of the navy, who was present, was able to converse easily with Rear Admiral Victor Blue of the Public Health Service in Washington, while all the company engaged in unrebuked eaves-dropping.
    The voice of the rear admiral was carried from his home in Washington to the radio station at Arlington, a distance of six miles, over the long-distance telephone wire from which it was automatically transferred to the wireless and conveyed to the laboratory of the Western Electric Company at 463 West street, in New York. It was then shifted, automatically, after it had traversed 225 miles of air, to the telephone wires, and made its way to the Lotos Club in West Fifty-seventh street, a distance of less than three miles. The secretary of the navy, recognizing the voice of the rear admiral, expressed sorrow over the outcome of the Army and Navy football game.
    Mr. Daniels said that these were days in which prophecies were realized, when he rose to speak of the wonders which had been accomplished by Mr. Carty and his associates in perfecting communication by wire and air, for he declared that wireless telephony would soon extend around the world.
    "We thought," he said, "that wireless telegraphy was the last of modern miracles that had to do with communication. Recently the world was amazed when from Washington, without wires, the human voice was heard in San Francisco. When fully perfected, we may talk to our friends 'from Greenland's icy mountains to India's coral strands.
    "The genius who is making this miracle possible is John J. Carty, to whom the Lotos Club pays tribute this evening."
    Frank R. Lawrence, the president of the Lotos Club, presided at the dinner. At his right was Mr. Carty and at his left the secretary of the navy.
    Others at the speakers' table were Frank J. Sprague, Melville E. Stone, John P. Gavit, Chester S. Lord and Charles W. Price. Among other members and guests present were N. C. Kingsbury, B. E. Sunny, H. B. Thayer, A. S. Hibbard, Thomas D. Lockwood, F. H. Bethell, Thomas B. Doolittle, Bancroft Gherardi, H. A. Halligan, F. B. Jewett, F. A. Pickernell, A. L. Salt, C. E. Scribner, Gerard Swope, John I. Waterbury, H. J. Pettingell.
    Among the other speakers were Theodore N. Vail, Captain William H. G. Bullard of the United States Navy, Colonel Samuel Reber of the Army, and Union N. Bethell.
    Most of the speech of Mr. Carty was directed to the universe. Through the transmitter he talked familiarly with his associates and subordinates all over the country, acting as a master of ceremonies in a realm of magic.
    A photographic reproduction of this diagram was presented to each of those present at the dinner at the Lotus Club, New York, on November 27th, to John J. Carty, chief engineer of the American Telephone and Telegraph Company. The diagram represents the wire and ether connections between the Lotus Club at New York and the radio station and residence of Rear Admiral Blue at Washington, D. C. The telephone conversation from New York to Washington was over the wire line and the conversation was transmitted through space from Washington to New York. Every word that came via wireless was clearly heard and understood in New York.
transmission diagram
    Mr. Vail said: "I cannot refrain from saying a few words in appreciation of this most delightful and considerate tribute to the foremost genius in electrical personal intercommunication--Our Carty. We, that is, all of us associated in that organization called the Bell System, associates who act and think and work together, are very proud of our Carty and are honored bv anything that honors him.
    "When our Carty was born electrical science was in its swaddling clothes, still being nursed in the laboratories of scientific institutions.
    "There were a few, who were looked upon as dreamers, outside these laboratories trying to teach the art how to walk and work--were trying to develop its industrial activity. Such men as Bell, Edison, Brush, Thomson and many other now notable names, were not then names to conjure with as they afterward became.
    "And yet so rapid has been this development that those same men who were the beginners are yet in their prime of active life.
    "Our Carty came with the telephone while it was yet being taught to speak, and has been either a co-laborer or leader in the development of that perfect comprehensive world-wide electrical conversational intercommunication which is rapidly bringing the whole world and its people within speaking distance.
    "While in the establishing of the methods for bringing all people together for electrical speech our Carty has been the most useful and constructive, and is now considered by all the foremost genius in this work, his work has by no means been confined to that branch, for in all other and collateral electrical development, whether affecting his particular work or not, he has been recognized as having a grasp of conditions to be overcome and a vision of what may be accomplished which few possess.
    "This tribute, from this club, is unique in that it is not a scientific tribute from fellow scientists; it is not a commercial tribute from corporation or association, but it is a layman's tribute, to one who is recognized and acknowledged as having made their business and social intercourse more easy, more comfortable and more agreeable and contributed so important an element into their daily life.
    "And as one member of the associates who claim Carty as ours, I want to thank you, Mr. President and members of the Lotos Club, for all."
    Three weeks prior to the demonstration described above, Secretary Daniels, in Washington, had transmitted the first official departmental order by wireless telephone. Secretary Daniels was sitting at his desk in the Navy Department and personally dictated the order into the mouthpiece of a telephone transmitter. The message traveled over a land telephone wire to the Bell telephone office in Washington, when it passed over a telephone wire to the naval radio station at Arlington, Va.
    Automatically the message was transferred from the telephone wire at Arlington to the antennae of the radio station and sent through the air to New York City. The message was picked up by the antennae of the radio station on the building of the Western Electric Company in New York, where it was automatically picked up by land telephone wires, and transmitted by land wires to the office of Rear Admiral Usher in the Brooklyn Navy Yard.