Tesla began his work on mechanical oscillators back in 1883. It was publicly displayed on World exhibition in Chicago, ten years later, in 1893. He began to explore the possibilities of applying mechanical oscillator in a purely mechanical sense – as a generator of mechanical oscillations. Tesla examined the possibilities of mechanical resonance. One of his oscillators, attached to the supporting column of the building, entered resonant oscillation, and so there was an artificial earthquake that was felt in several adjacent buildings.