(last bread)
https://www.forbes.com/sites/davidbressan/2020/01/07/nikola-teslas-earthquake-machine/
"He put his little vibrator in his coat-pocket and went out to hunt a half-erected steel building. Down in the Wall Street district, he found one, ten stories of steel framework without a brick or a stone laid around it. He clamped the vibrator to one of the beams, and fussed with the adjustment until he got it.
Tesla said finally the structure began to creak and weave and the steel-workers came to the ground panic-stricken, believing that there had been an earthquake. Police was called out. Tesla put the vibrator in his pocket and went away. Ten minutes more and he could have laid the building in the street. And, with the same vibrator, he could have dropped the Brooklyn Bridge into the East River in less than an hour."