English: High voltage expert Henry Transtrom in 1913 demonstrating a brush discharge from his fingers, while touching the high voltage terminal of a Tesla coil (not shown) with his other hand. The writhing sparks are 10 inches (25 cm) long, violet in color. The Tesla coil applied a voltage of 50 kV to 100 kV of alternating current at a frequency of 100 kHz to 1 MHz to his body. Frequencies above 10 kHz such as Tesla currents do not cause the physiological sensation of electric shock, but the experiment could cause painful RF burns on the fingertips. During the early 20th century carnival and circus sideshow performers with names like Dr. Resisto, The Great Volta and Madam Electra charged their bodies with hundreds of thousands of volts from a Tesla coil to perform spectacular stunts like this. It used to be thought that due to skin effect, high frequency current from a Tesla coil traveled along the surface of the body so it could cause burns but not electrocution, but it is now known that this is not true. Passing Tesla currents through the body like this is now considered extremely dangerous and unhealthy. DON'T TRY THIS