The local builder at Roddy’s orders put up a mast upon the tower immediately above the room they had chosen, and the young man having constructed the double-line aerial a hundred feet long and put many insulators of both ebonite and porcelain at each end, the long twin wires were one morning hoisted to the pole, while the other end was secured in the top of a great Wellingtonia not far from the mansion. The lead-in cable, known to naval wireless men as the “cow-tail,” was brought on to a well-insulated brass rod which passed through the window-frame and so on to the instruments, which Roddy set up neatly in an American roll-top desk as being convenient to exclude the dust.
Making a wireless “earth” proved an amusing diversion to both. Elma, who had read a book about wireless, suggested soldering a wire to the water tap; but Roddy, who had bought his experience in wireless after many months and even years of experiment, replied:
“Yes. That’s all very well for an amateur ‘earth,’ but we’ve put up a professional set, and we must make a real ‘earth.’”
The real “earth” consisted, first, of digging three deep holes about four feet deep and three feet long under the aerial. This necessitated the use of a pickaxe borrowed from the head gardener, for they had to dig into chalk.
Elma proved herself an enthusiastic excavator and very handy with the shovel, and after a heavy afternoon’s work she wheeled a barrowful of coke from the palm-house furnace, and Roddy carefully placed a zinc plate in a perpendicular position into each hole and surrounded it with coke which, absorbing the moisture, would always keep the zinc damp, and hence make a good earth connexion. These three plates having been put in directly beneath the aerial wires, they were connected by soldered wires, and before darkness set in the earth-wire was brought in and connected up to the set.
Afterwards, in order to make certain of his “earth”—usually one of the most neglected portions of a wireless installation, by the way—he took a large mat of fine copper gauze which he had bought in London, and soldering a lead to it spread it across the grass, also beneath the aerial.
Elma watched it all in wonderment and in admiration of Roddy’s scientific knowledge. She had read the elementary book upon wireless, but her lover, discarding the directions there set down, had put in things which she did not understand.
“And now will it really work?” asked the girl, as together they stood in the little room where upon the oak writing-desk the various complicated-looking pieces of apparatus had been screwed down.
“Let’s try,” said Roddy, screwing two pairs of head-’phones upon two brass terminals on one of the units of the apparatus.
Elma took one pair of telephones, while Roddy placed the others over his ears. His deft fingers pulled over the aerial switch, whereupon the nine little tubular electric lights instantly glowed, each of them three inches long and about the size of a chemical test-tube. They gave quite a pretty effect.