Page:Wireless Telegraphy and Telephony (1908, Massie and Underhill).djvu/30

9. The Spark-gap

The device through which the oscillatory discharge of the Leyden jars takes place is known as the spark-gap. This consists of two metal rods insulated from one another, and with their ends about one inch apart, although this

Fig. 6.—Spark-gap with Muffler, Surrounded by Inductance.

distance may be varied at will by means of an adjusting device.

As the high-frequency discharge across the spark-gap emits a loud, crashing sound, it is usually surrounded