How does Zhang Heng seismograph work?

To indicate the direction of a distant earthquake, Zhang’s device dropped a bronze ball from one of eight tubed projections shaped as dragon heads; the ball fell into the mouth of a corresponding metal object shaped as a toad, each representing direction in which the seismic wave was travelling.

Why did Zhang Heng invent the seismometer?

In 132, Zhang introduced an intricate seismometer to the court, which he claimed could detect the precise cardinal direction of a distant earthquake. On one occasion his device indicated that an earthquake had occurred in the northwest.

What did Zhang Heng discover?

He invented the world’s first water-powered armillary sphere to assist astronomical observation; improved the inflow water clock by adding another tank; and invented the world’s first seismoscope, which discerned the cardinal direction of an earthquake 500 km (310 mi) away.

When did Zhang Heng invent the seismograph?

AD 132
So it was that Chang Heng, astronomer royal to the Han Dynasty, invented an accurate seismograph in AD 132 — 1600 years before anyone in the West did. It was a large bronze urn with eight dragon heads gazing outward in eight directions.

What is Zhang Heng known for?

Zhang Heng, Wade-Giles romanization Chang Heng, (born 78 ce—died 139), Chinese mathematician, astronomer, and geographer. His seismoscope for registering earthquakes was apparently cylindrical in shape, with eight dragons’ heads arranged around its upper circumference, each with a ball in its mouth.

How does a seismometer work?

A seismometer is a device that is sensitive to vibrations. It works on the principle of a pendulum: a heavy, inert mass with a certain resistance to movement (i.e. inertia) due to its weight is suspended from a frame by a spring that allows movement.

Why were Zhang Heng accomplishments important?

In 132 Zhang invented the first seismograph for measuring earthquakes. He was even able to indicate that the earthquake was to the west of the capital. He achieved fame when reports of an earthquake more than a thousand kilometres north west reached the capital several days later.

How did the first seismometer work?

The First Earthquake Detectors Whenever there was even a slight earth tremor, a mechanism inside the seismograph would open the mouth of one dragon. The bronze ball would fall into the open mouth of one of the toads, making enough noise to alert someone that an earthquake had just happened.

Where are seismographs located?

A seismograph is an instrument for measuring earthquake (seismic) waves. They are held in a very solid position, either on the bedrock or on a concrete base.

When did Seismology begin?

The science of seismology was born about 100 yr ago (1889) when the first te- leseismic record was identified by Ernst yon Rebeur-Pasebwitz at Potsdam, and the prototype of the modern seismograph was developed by John Milne and his associates in Japan.

What was Zhang Heng’s seismograph made of?

The bronze device featured eight metal dragons attached to what looked like a big coffee urn. Each dragon’s head pointed in a different direction (north, south, east, west, northeast, southeast, southwest, and northwest), and each had a copper ball in its mouth.