“That’s nothin’,” grinned the driver, who had overheard this remark. “We was takin’ it easy all de way. If you guys had been in a hurry, now, I might have shown you a little speed.”
“Well, you did pretty well, as it was,” said Bob. “You were in a hurry, if we weren’t.”
Larry paid the man, and he was off at top speed and had disappeared around a corner before Larry had fairly put his change away.
“That must be a great life, driving a taxi all day in a big city,” said Larry. “But let’s go in, and see if we can find the boss. I hope he’ll act tip nice and show you fellows the whole works. I’ll go around with you and try to look wise, but I won’t have any idea of what it’s all about.”
Entering the office, they had little difficulty in seeing the manager, and he readily consented to have the boys look over the station, turning them over to an assistant, as he was too busy to take them around himself.
Mr. Reed, the assistant, did not appear particularly pleased with his assignment at first, but when he found that the boys were well grounded in radio, his attitude changed.
“I get tired of showing people around who don’t know a thing about radio, and do nothing but ask fool questions,” he explained. “But when I get 193 some one who knows the subject and can understand what I’m showing him, that’s a different matter.”
He showed them over the sending station from the studio to the roof. The boys listened with the keenest interest as he described to them the methods by which the broadcasting was carried on, which every night delighted hundreds of thousands of people within range of the station.
In a little room close to the roof they saw the sending apparatus which really did the work. There was a series of five vacuum bulbs through which the current passed, receiving a vastly greater amplification from each, until from the final one it climbed into the antenna and was flung into space. To the casual onlooker they would have seemed like simply so many ordinary electric bulbs arranged in a row and glowing with, perhaps, unusual brilliance.
But the boys knew that they were vastly more than this. Where the electric light tube would have contained only the filament, these tubes at which they were looking contained also a plate and a grid—the latter being that magical invention which had worked a complete revolution in the science of radio and had made broadcasting possible. From the heated filament electrons were shot off in a stream toward the plate, and by the wonder-working intervention of the grid were 194 amplified immeasurably in power and then passed on to the other tube, which in turn passed it on to a third, and so on until the sound that had started as the ordinary tone of a human voice had been magnified many thousands of times. This little series of tubes was able to make the crawl of a fly sound like the tread of an elephant and there is no doubt that a time will come when through this agency the drop of a pin in New York City can be heard in San Francisco.