Nuremburg, Germany, 1650. A firework display. There is in fact fireworks going off, but look closer.
The weapons that the men have are not fireworks. Those are swords that are used as electricity conductors, electricity of which is harnessed from the altar in the middle. The swords are even shaped like lightning bolts.
It is a surprise that this illustration wasn't quickly hidden. It clearly shows electricity harnessing, and they just call this a simple firework display hoping no one would look closer at the illustration.

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