The Advance Shock Machine Penny Arcade Shocker Antique uses real electricity to shock the person using it. Shock machines were common at penny arcades during the first half of the 20th century. To use the machine, you insert a coin and then hold onto the two metal knobs as the intensity of the electrical shock increases. As you can see in the video, holding onto the machine becomes pretty unbearable after a certain point. I wonder how often an arcade-goer was able to endure one of these machines up to the highest level of electricity.
[Note from Mark – Does anyone else remember that Disneyland had one of these in its penny arcade in the 1970s? I tried it when I was about 10 years old and the electricity caused my hands to grip tightly to the knobs so I couldn't let go. When the meter hit the maximum output it didn't turn off. I thought I was going to die. My mother saved me by pushing my arm and breaking the circuit. By the 1980s Disneyland had removed the electrical circuit and replaced with with a vibrator to simulate the feeling of electricity.]