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Handmade Earthquake Alarm Science Experiment DIY Assembly Toy Wooden Children EducationalToys Birthday Gifts Seismograph knowledge:
The world's first seismic instrument. In AD 132, Zhang Heng, the scientist of Eastern Han Dynasty, invented the world's first seismic instrument-seismometer and was verified in practical applications. Unfortunately, physical objects and patterns of the seismograph were lost. Only written records were left, and the physical objects were riddled with mysteries.
Earthquake alarm principle: When shaking small production, the copper wire of the glass beads will contact with the O-shaped lamp, the line is connected, and the buzzer sounds. Tip: This material does not contain two AA batteries, please bring your own.
Notes:
Due to the different display and different light, the picture may not show the actual color of the item. Thanks for your understanding.