PREVIEW
... cal content also began to emerge.
For instance, the electric fan was one of these unexpected products, invented by a technician.
The initial reason was for cooling down machinery. He found mechanical fans inconvenient and aimed to create a fan that did not require manual operation.
With a bright idea, he attached a metal blade to an electric motor, and once powered, the blades spun rapidly—thus, the earliest electric fan was born.
Franz initially thought another g ...
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