Then he turned down the big aerial switch which sent the incoming currents to earth and acted as a protection to his instruments against either lightning or “strays.” And closing the door of the room, he went to put on evening clothes.

When Professor Falconer and his son entered Mrs. Beverley’s fine house in Upper Brook Street it was nearly half-past nine. As the door opened there came the strains of an orchestra. Mrs. Beverley was the widow of a wealthy banker of Buenos Ayres, after whose death she had brought her daughter Sylvia to London where she had quickly become popular as a hostess, attracting about her all sorts of men and women who had “done something.”

When one was invited to Mrs. Beverley’s parties one was certain of meeting interesting people—lions of the moment—whose faces peered out at one from all the picture papers—people in every walk of life, but all distinguished, if even by their vices.

“Hulloa, Geoffrey!” exclaimed a slim, dark-haired young girl in a flame-coloured dance-frock and a charming hair ornament of gilt leaves. The dress was sleeveless and cut daringly low in the corsage and the back. “I thought you’d forgotten us!”

“Well, Sylvia, I’ll confess,” said Geoffrey in a low voice, taking the hand she held out to him. “As a matter of fact, I really had! The pater only reminded me of it just in time for us to rush to the station.”

“Ah! Immersed as usual in your mysterious old wireless,” laughed the pretty daughter of the South American widow. “I heard somebody say at a lunch at the Ritz the other day that all electrical people inevitably take to drink or to wireless.”

“Well, I’m glad I haven’t yet taken to the former,” laughed the young man, and together they went into the fine drawing-room, where a gay dance was in progress.

A few moments later the young man found his hostess, a stout, well-dressed woman, who possessed all the impelling manners of the well-bred South American, and who had hustled into Society until the newspapers were constantly chronicling her doings, describing her jewels, and printing her photograph, so that Suburbia knew more of Mrs. Beverley than even Mrs. Beverley knew herself. She loved Argentina, she confessed, but she loved London far better. Before her marriage she had known quite a lot of people in London society, for she had come over each year, and now, in her widowhood, she had returned, and certainly she was one of London’s prominent figures, for she entertained Cabinet Ministers, politicians, authors, painters—in fact, anybody who was anybody in London life.

Geoffrey had first met her and her daughter while on the voyage from New York eighteen months before. He had been over on business to the transatlantic Wireless Station at Belmar—which, by the way, is in direct communication with Carnarvon by day and night—and on board they had been introduced, with the result that the widow had invited him to call upon her “when she settled down.”

The pretty go-ahead Sylvia had attracted him, and when one day he had received a card at the Automobile Club he lost no time in resuming the very pleasant acquaintanceship. Indeed, Mrs. Beverley and Sylvia had motored down to Warley one day a month afterwards, and looked in at Geoffrey’s experimental laboratory, bewildered at its maze of instruments, its many little glow-lamps and tangles of wire.