6 Houfeng Didong Yi – The Earthquake Detector 

Created by the “Leonardo da Vinci of China,” aka Zhang Heng, The Houfeng Didong is the first earthquake-detection device dating back to 2,000 years ago. The seismoscope featured a large bronze device that produced a loud sound after dropping a ball into a bronze container every time an earthquake was detected. The direction of the earthquake was then known by examining the container.

The Houfeng Didong Yi is the oldest known seismoscope and one of the most thrilling ancient technologies from China that dates back to 2,000 years ago. Invented by Zhang Heng of the Han dynasty in 132 CE, it was a large bronze vessel with a diameter of about 2 meters.

At the top of the vessel were dragon’s heads holding bronze balls. When an earthquake would happen, one of eight tubed projections would drop its ball into the corresponding bronze container situated at the base,  making a sound. This would also supposedly show the direction of the seismic waves. 

The available text says Zhang’s device featured eight arms connected with cranks. When tripped, a crank would raise the dragon’s head due to its catch mechanism and eventually release a ball from its lower jaw. 

This instrument could detect seismic waves from hundreds of kilometers away. Unfortunately, the physical remains of the device no longer exist. (1, 2)

7 Ancient Greek Automatic Doors

Alexandria in ancient Greece in the 1st century CE had automatic temple doors. The doors were invented by Heron of Alexandria who used a clever hydraulic system to open and close the doors. The chief purpose of these doors was to create a sense of mysticism among the temple devotees. 

In the 1st century CE, Heron of Alexandria, a mathematician and engineer in Roman Egypt, invented the first known automatic door. The doors were set up in a temple in Alexandria, a Greek colony at the time. Heron suspended a brass pot filled with water under the fire burning at the altar.

When the temple’s priest would light the fire, the pressure built up in the pot causing it to force water into the attached containers. As these containers were attached to a pulley system, they acted as weights. Once the containers were full, they would drag down the pulley and open the temple doors. 

The doors would open once a day at the time people arrived at the temple to offer their prayers. However, the whole system would take many hours to execute the successful opening of the temple doors. (source)

8 Ancient Chinese Drilling Technology

Around 2,000 years ago, deep drilling, one of the ancient technologies to drill salt and natural gas from the earth, originated in China’s Sichuan Province. The cable drilling system called “churn” bored large holes in the ground. In mining, it was drilled into carbonate rocks of zinc and lead to extract samples of the ore.

The ancient drilling technology was first developed in China’s Sichuan Province about 2,000 years ago, with the motive to extract salt from the earth. The system employed in the drilling was called “churn” and featured a bamboo pipe and rig, and an iron drill bit.

One or more men would stand on the plank lever and lift the drill stem to about a meter. The pipe would then drop and the drill bit would crash down into the rock, eventually pulverizing it. This process would go slowly, month by month. 

At regular intervals, mud and crushed rock from the bottom of the hole used to be removed. The drill stem would then be pulled from the hole and a hollow bamboo with a valve would be lowered to the bottom of the hole. The mud inside the lifted tube kept the valve closed which would help to bring contents to the surface. Laborers would then restart the drilling to extract brine. The saline water when evaporated using a heat source would leave the salt behind.

The ancient Chinese drilling system experienced a major breakthrough around 1050 CE when the bamboo pipe was replaced with a light and thin cable. This lowered the weight required to be lifted from the ground and eventually increased the depth being drilled. At the end of the 18th century, the setting up of the “Kang Pen” drum on the top of the wellhead yielded brine and gas simultaneously. (1, 2, 3)

9 Water Mill

The use of a water mill was pioneered by the Greeks in the form of a water wheel during the 1st century BCE. The water wheel used flowing or falling water to create power through paddles and a vertical shaft. The horizontal wheel model paved the way for the “Roman mill” that featured a vertical wheel on a horizontal shaft. 

During the 1st century BCE,  the Greek epigrammatist Antipater of Thessalonica referred to a horizontal waterwheel. Then, in 14 CE, a Roman engineer named Vitruvius created a water wheel with a horizontally-mounted shaft. Although the “Greek” model was much simpler, it worked well with only small diameter millstones. As it was inefficient, it was replaced by water wheels of the vertical design.

Both the water wheels used hydropower to drive mechanical processes through paddles mounted around the wheel. The force of the water moved the paddles and consequently rotated the wheel. The shaft of the wheel transmitted this consequent rotation of the wheel to machinery. 

Roman-style mills utilized a gearing mechanism and were more complicated. However, they were successfully used for agriculture, mining, and construction purposes. (1, 2)

10 Zhuge Crossbow aka “The Repeating Crossbow”

Zhuge crossbow, or the repeating crossbow, is a crossbow invented in ancient China during the Warring States period (475-220 BCE). It combined bolt placing, bow spanning, and shooting into one motion. The repeating crossbow was generally a non-military weapon used for hunting and fighting robbers.

The repeating crossbow was invented in the State of Chu during the Warring States Period in the 4th century BCE. It acquired the name “Zhuge crossbow” due to its association with military strategist, Zhuge Liang (181–234 CE), although its invention has nothing to do with him. 

The basic construction consists of a double magazine on top of a tiller and a pistol-style grip at the bottom. A sliding lever with a handle tied to the chord is used for arming and shooting. Just like a normal bow, the user holds the pistol grip with one hand and pulls the level back and forth with the other hand. The lever of the crossbow is equipped with a mental trigger.

When the lever goes forward, the trigger goes along with it to catch the drawstring and becomes locked firm due to friction. Upon being drawn back, the double magazine feeds two bolts to the firing slots attached on either side of the trigger. The sear then touches a round bar holding the lever in place at the end of the pulling action. The bar pushes the sear allowing it to release the trigger and the two loaded bolts. 

The repeating crossbow has a maximum range of 180 meters. Its short range limited its use for high-end defensive purposes. However, the crossbow was still used to safeguard households against robbers. (source)