After ten years Tesla began to experiment with high frequencies.
The Tesla Coil which he had patented in 1890 was capable of raising
voltages to unheard of levels such as 300,000 volts. Edison, who was
still generating D.C., claimed A.C. was dangerous and to prove it
contracted with the government to produce the first electric chair
using A.C. for the execution of murderers condemned to death. When it
was first used it was a ghastly flop. The condemned man moaned and
groaned and foamed at the mouth. After four minutes of repeated
application of the A.C.voltage smoke began to come out of his back.
It was obvious that the victim had suffered a horribly drawn-out
death.

Tesla said he could prove that A.C. was not dangerous. He gave a
demonstration of high voltage electricity flowing harmlessly over his
body. But in reality, he cheated, because he had used a frequency of
10,000 cycles (10 kHz) at extremely low current and because of the
skin effect suffered no harm.

One of Tesla's patents related to a system of lighting using glass
tubes filled with fluorine (not neon) excited by H.F.voltages. His
workshop was lit by this method. Several years before Wilhelm
Roentgen demonstrated his system of X-rays Tesla had been taking
photographs of the bones in his hand and his foot from up to 40 feet
away using H.F.currents.

More astonishing still is the fact that in 1893, two years before
Marconi demonstrated his system of wireless signaling, Tesla had
built a model boat in which he combined power to drive it with radio
control and robotics. He put the small boat in a lake in Madison
Square Gardens in New York. Standing on the shore with a control box,
he invited onlookers to suggest movements. He was able to make the
boat go forwards and backwards and round in circles. We all know how
model cars and aircraft are controlled by radio today, but when Tesla
did it a century ago the motor car had not been invented, and the only
method by which man could cover long distances was on horseback!

Many people believe that a modification of Tesla's 'Magnifying
Transmitter' was used by the Soviet Union when suddenly one day in
October 1976 they produced an amazing noise which blotted out all
radio transmissions between 6 and 20 MHz. (The Woodpecker) The
B.B.C., the N.B.C. and most broadcasting and telecommunication
organisations of the world complained to Moscow (the noise had
persisted continuously for 10 hou