Page:Jack Heaton, Wireless Operator (Collins, 1919).djvu/125

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Working with Marconi
101

while light waves are in the neighborhood of the ten-millionth of an inch in length, wireless waves are so long they make no impression at all on the eye.

That light is electric waves in the ether has been known for the last couple of hundred years and later on scientific sharks believed there were other and longer electric waves but they didn’t know how to produce them or to receive them until 1888.

In that year Heinrich Hertz, a young German college professor, discovered that when an electric spark was made by any kind of an apparatus the positive and negative electric charges in uniting together would not only break down the air to make the spark, but would form an oscillating current, that is, a current which surges to and fro hundreds of thousands of times a second, and that this high frequency current, as it is called, sets up waves in the ether just as the vibrations of a bell set up waves in the air.

Hertz made an apparatus by which he could produce electric waves of different lengths and this he called an oscillator. It consisted of a couple of wires fixed to the balls of the spark-