By the elastic licence granted to him as an experimenter by the General Post Office Geoffrey had been allowed to erect high twin aerial wires double the length of the official regulation of one hundred feet, and these, suspended from poles placed in the tops of two of the high Wellingtonias, were brought across the wide lawn to the rear of the house, and down into the room in which the young man was seated.
“Always the same long drawn-out note at exactly the same time!” he went on. “Eleven-and-a-half minutes before ‘F.L.’ sends his weather report. What, I wonder, can it mean?”
From the Eiffel Tower, whose call-letters in the radio-telegraphic code are “F.L.,” weather reports from western Europe are each evening sent out upon so powerful a note that they are read on the opposite side of the Atlantic. Young Falconer, therefore, fell to wondering whether those strange signals he heard nightly, and which were so unaccountable, were not in some way connected with the transmission from Paris.
The eleven-and-a-half minutes passed, and just as the Eiffel Tower began to call in that peculiar cock-crowing note which all wireless men know so well, his father entered.
“Hulloa, Geoff! I thought you had gone up to town—it’s Mrs. Beverley’s dance, is it not?”
“Yes,” replied the young radio-engineer; “but I’ve just been listening. I’ve tuned in that same strange signal as last night. It is really most curious.”
“Automatic transmission, perhaps,” replied the alert, white-bearded old gentlemen. “Did you not say that there were some transmissions at a hundred words a minute in progress?”
“Yes, Witham and Farnborough. But I have heard them many times during the past few weeks. I know the note of Farnborough. Besides, his wave-length is different. This mysterious signal is on eleven hundred mètres—a continuous wave—above the ships and the Air Ministry.”
“And nobody else hears it except yourself?” asked the lean, deep-eyed old man, who possessed such wide scientific knowledge, though he admitted that wireless was a branch with which he was not familiar. Radio-telegraphy was a new science, fresh discoveries being made daily by those who, like his son, were engaged in active research work.