The Wireless Age, June, 1914, page 725:
New York to Philadelphia by Wireless Telephone
W IRELESS operators at Sandy Hook, Sea Gate and on ships leaving the harbor, together with scores of amateur wireless enthusiasts in Greater New York and along the Jersey coast, were mystified on the afternoon of May 13th by overhearing through their receivers the voice of Caruso singing. This was possible because the head piece receiver used in wireless telephony is similar in principle to that used in telegraphy.
Most of the delighted ones did not know to whom they were indebted for the canned solos of the great tenor, but it wasn't long before some of them found out that the concert was a part of a wireless telephone test made by the Marconi Wireless Telegraph Company at its station on the roof of the Wanamaker store in New York. Not only were the tenor's phonographic tones clearly heard by the operator at the wireless station at the Wanamaker store in Philadelphia but a commercial message, dealing with ordinary business of the day, was communicated by voice through the air for the first time from New York to Philadelphia.
Incidentally the Marconi people had a talk with the Southern Pacific steamship Antilles, which sailed at noon for New Orleans. At 4 o'clock a wireless was received from David Sarnoff, aboard the Antilles, saying that the telephonic operatic selections sent out from the Wanamaker station had been "received."
At twenty-five minutes to eight o'clock in the evening a cable message from Vera Cruz was telephoned by wireless to the Antilles and the ship's operator got it when the ship was about seventy-five miles off the Scotland lightship. He relayed it by wireless to the Marconi station at Cape May, from which point confirmation of its receipt was telephoned to the New York senders. The cable read as follows:
"The following cable has been received: Admiral Mayo reports that Tampico will fall by 9 o'clock to-night. The Federal gunboats Vera Cruz and Bravo are pulling out of the river and going to sea, leaving Tampico to its fate. People are now leaving the city before its fall."
The tests were made by Frank A. Hart and H. Ernest Campbell of the engineering department of the Marconi company, Roland Crane, one of the company's wireless operators, was in charge of the station. The tests started soon after the Antilles started on her journey.
It wasn't long before wireless men waiting for ordinary marconigrams began to hear through their receivers the voice of Caruso and the sound of a man talking and counting slowly and deliberately. They knew of course that they were picking up wireless telephone tests and then they started to wireless around to find out at what station the experiments were being made. When the word got around that the Wanamaker store in New York was communicating by wireless telephone to the Philadelphia store, Messrs. Hart and Campbell began to receive inquiries by old-fashioned telephone as to what was going on.
There was sending only and no receiving in the experimenting in New York. After a message had been sent out the operator in the Philadelphia store would reply by wireless telegraphy that it had been received and then he would repeat what was said.
The operatic music was sent on its way to delight the ears of operators aboard ships by placing the trumpet of a phonograph close against the sender of the telephone apparatus.
The Marconi company recently received word from London saying that Mr. Marconi had completed his wireless telephone tests and that the apparatus was an entire success. The British company will now begin construction of sets for the Italian navy. They are guaranteed to maintain communication between ships over a distance of about thirty-two miles, although in practice they have been tried successfully over a much greater distance.