Historical Science & Technology, World-Changing Inventions

Ancient China’s Four Great Inventions

Compass. Gunpowder. Papermaking. Printing. Together, these are the Four Great Inventions of ancient China, still celebrated in Chinese culture today for their historical significance to world civilization as a whole. The Four Great Inventions were popularized by Joseph Needham, a British biochemist, historian,  and noted expert on the science and civilization of ancient China.

Origins of the Four Great Inventions

Credit for the invention of three of the Four Great Inventions was originally given to European sources. Printing, firearms (gunpowder), and the compass were originally known to Europeans as the cleverly-named Three Great Inventions.

However, as Spanish and Portuguese sailors returned to Europe from Asia in the 1530s, they brought claims that all three inventions had been part of Chinese civilization for centuries. Perhaps unsurprisingly, Europeans continued to make conflicting claims as to the inventions’ origins.

In 1620, Francis Bacon wrote that “printing, gunpowder, and the nautical compass…have altered the face and state of the world.” Karl Marx commented on the inventions’ importance in the 19th century, stating “Gunpowder, the compass, and the printing press were the three great inventions which ushered in bourgeois society.”

By the end of the 19th century, scholars were commonly giving credit for the Three Great Inventions to the correct source—China.

Compass, Gunpowder, Papermaking, Printing

A book from China’s Song dynasty, dated around 1040 CE, contains the first reference to a magnetic device being used to find direction. A later work, dated 1088 CE, gives the first written account of a true suspended magnetic needle compass. (Chinese literature’s first reference to magnetism itself comes from the 4th century BCE tome Book of the Devil Valley Master). Unique designs for both wet and dry compasses were developed in China around this time.

Chinese alchemists inadvertently created gunpowder in the 9th century CE. By the end of the 12th century CE, a number of gunpowder formulations had been developed, including a variety powerful enough to explode cast iron containers (the first grenade-like bombs). By the mid-1400s, Chinese scientists had perfected the mixing of gunpowder, leading to several different formulas that achieved the mixture’s maximum explosive potential.

Papermaking in China has been traced back as far as 8 BCE. Paper made from various plant fibers was widely used for wrapping and padding as far back as the 2nd century BCE. Paper’s use as a writing medium grew throughout the 3rd century BCE, and by the 6th century CE toilet paper was commonly used. Paper tea bags were used in China beginning during the Tang Dynasty (618-907 CE), and paper currency was first used during the Song Dynasty (960-1279 CE).

Chinese Woodblock Printing

Woodblock printing for textiles was invented in China around 220 CE. Woodblock printing for text was developed in 868 CE, evidenced by the first printed book, “The Diamond Sutra,” which was produced in that year. Though the Chinese also invented moveable type, woodblock printing was better suited to Chinese characters. Western-style printing presses were not widely used in China until the 19th century, roughly 300 years after their invention.

Historical Significance

In recent years, scholars—particularly Chinese scholars—have begun to question the overall greatness of the Four Great Inventions. It is suggested that the emphasis placed on these inventions overshadows other Chinese inventions of equal or potentially greater significance to China’s development and the world at large. Other inventions such as iron and copper metallurgy, astronomy, mathematics, wine making, and coal and petroleum exploitation are often given as examples of this.

Photo credit: Foter / Public Domain Mark 1.0

Historical Science & Technology, Technology

Stone Tools: Mankind’s First Technology

Stone tools are the first and most basic form of technology that humans ever invented. It is from their initial creation that the period of prehistory known as the Stone Age derives its name, though there are still some stone tool-dependent cultures in existence today.

Thank You, Ancient Tanzanian Flintknappers

Stone tools take many forms: hammers, arrow heads, knives, etc. These tools are can made with ground or chipped stone, though chipped stone is more common and more versatile. Stone toolmakers are known as flintknappers.

The oldest stone tools archeologists have discovered come from the Oldvuai Gorge in Tanzania. Known as Olduwan tools, they are extremely simple and generally cone shaped. River pebbles and other similar stones were struck with larger, sturdier hammer stones to remove flakes and create edges or sharp points.

stone tools

The oldest Olduwan stone tools date back 2.6 million years; these were discovered near Gona in Ethiopia. From there, stone tool “technology” spread widely throughout the ancient African continent, reaching Eurasia roughly 1.8 million years ago.

Acheulean Tools

The first examples of more complex stone tools, dubbed Acheulean tools after the region in France where they were first discovered, were created roughly 1.7 million years ago. Though the “technology” overlapped with Olduwan tools somewhat, Acheulean tools exhibit evidence of a more thought-out, deliberate manufacturing process.

Larger stones were used as blanks from which large flakes, called cores, were removed. These cores were placed on anvil stones and struck with harder hammer stones to create rough shapes. These pieces were then reworked with smaller, often softer wood or bone hammers to refine the shape. In this way, two convex surfaces could be created, intersecting at a sharp edge.

These are the first examples of stone knives and slicing tools. Some archeological examples are leaf-shaped, round, or ovoid, but all are undeniably blades. It is assumed that these Acheulean tools were used mostly for butchering, as they had no handles and would not be very effective for killing prey.

Mousterian, Aurignacian & Microlithic Tools

First discovered near Le Moustier, France, in the 1860s, Mousterian stone tools eventually replaced Acheulean technology. Using the Levallois technique, smaller, sharper knife-like tools were created. These tools were likely developed by Neanderthals.

During the Upper Paleolithic period, longer blades began to appear. These tools were created by flintknappers of the Aurignacian culture beginning approximately 45,000 years ago.

Roughly 17,000 years ago, hafted stone tools (i.e., tools with handles) were developed by the Magdalenians. These Microlithic tools were much more effective as hunting devices and weapons, and made far more efficient use of flint and other available materials. However, greater skill was required, as smaller and smaller flakes of stone were used for these tools.

The Neolithic Era

Large, roughed-out flint axes first appeared during the Neolithic period. They were often polished to create a fine finish and a more effective cutting surface. Natural flint quarries offered plentiful materials for these flint axes. They were widely traded, and used across much of ancient Europe for forest clearance, leading to the establishment of settlements.

Photo credit: Dunechaser / Foter / Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Generic (CC BY-NC-SA 2.0)

Historical Science & Technology, Technology

Archimedes’ Screw: Hey, This is A Family Site!

Archimedes’ screw is a hand-operated machine used by the Ancient Greeks (and other cultures since their time) to raise water from low-lying bodies to higher elevations, usually for the purposes of irrigation. Also known as a screw pump, Archimedes’ screw is a simple yet effective device, modern variations of which can still be found in use today.

Invented By, Or Merely Credited To?

The invention of the screw pump is commonly attributed to Archimedes of Syracuse, a Greek polymath who lived in the 3rd Century BCE. However, historical records describe similar devices being used by the Assyrians over 350 years prior to Archimedes’ birth. It is possible that the device was simply unknown to the Greeks prior to that time, and that Archimedes merely mimicked the design of water pumps he saw in use during a visit to Egypt.

Either way, he must’ve done something right, because the device is still called the Archimedes’ screw 2,000-plus years later.

Simple, Yet Effective

A typical Archimedes’ screw is comprised of a flat, helical surface winding around a cylindrical center shaft (like a spiral staircase anchored to a center pole) enclosed in a hollow pipe. As the shaft turns, the bottom end of the screw surface scoops up water and slides it up the pipe until it reaches the top, where it pours out.

A modern Archimedes' screw, with open-top casing.

A modern Archimedes’ screw, with open-top casing.

Originally, screw pumps were operated by hand, but windmill- or water-powered designs soon followed. Some designs had the screw attached to the inside of the tube itself, with the whole device rotating as one, rather than the screw turning independently of the stationary tube. It is believed that this variation allowed the apparatus to be powered by human treading (i.e. people walking in place on top of the casing as it rotated).

Common Applications & Legacy

In addition to feeding irrigation systems, Archimedes’ screw was also used to drain water out of mines and other low lying areas. In the Netherlands, it was used to drain land that was underwater to create agricultural polders.

The auger device at the front of a snow blower is essentially an Archimedes’ screw turned on its side. Modern Archimedes’ screws are used in sewage treatment facilities. In 2001, a screw pump was used by British engineer John Burland to stabilize the Leaning Tower of Pisa. Perhaps most importantly of all, Archimedes’ screws are used in chocolate fountains.

Photo credit: ARG_Flickr / Foter / Creative Commons Attribution 2.0 Generic (CC BY 2.0)


A Modern History of Perpetual Motion Technology

The theory of perpetual motion has existed since at least Medieval times, and scientists and inventors have been trying—and failing—to produce perpetual motion machines since that time. Science proved decades ago that creating a true perpetual motion device is, in fact, impossible. However, this has not stopped people from trying. Here, we’ll look at relatively recent developments in this branch of speculative science.

1900-1950: Tesla & Perrigo

The brilliant and prolific Nikola Tesla claimed to have discovered an abstract principle on which perpetual motion machines could be based. In 1900, he wrote that, “A departure from known methods—[the] possibility of a ‘self-acting’ engine or machine, inanimate, yet capable, like a living being, of deriving energy from the medium—[is] the ideal way of obtaining motive power.” Despite this supposed breakthrough, Tesla never produced a machine based on his principle.


Nikola Tesla

Harry Perrigo, an MIT graduate, claimed to have invented a device that derived its energy source “from thin air” or from “aether waves.” Unlike Tesla, Perrigo actually built his machine, and even demonstrated it before Congress in December of 1917. A patent was pending for Perrigo’s “Improvement in Method and Apparatus for Accumulating and Transforming Ether Electric Energy” until investigators discovered that his device had a motor battery hidden inside it.

1951-2000: Franch, Papp & Many Others

Guido Franch claimed to have invented a new process of turning water molecules into high-octane gasoline (called Mota fuel) in the early 1950s. He was acquitted of fraud in 1954, but was convicted in a new trial in 1973.

In the mid-‘60s, Josef Papp claimed to have invented an automobile engine that ran on inert gas. A public demonstration was given for investors and potential investors in 1966; the engine exploded, killing one investor and injuring two others. Papp somehow continue to collect money from investors, but another engine was never publicly demonstrated.

Physicist Richard Feynman theorized a Brownian ratchet capable of extracting meaningful work from Brownian motion (the random motion of particles suspended in a liquid or gas) in 1962. At the same time, he demonstrated how said device would inevitably fail in actual practice.

Richard Feynman (center)

Richard Feynman (center)

In April 1979, Howard Robert Johnson received a US Patent for a permanent magnet motor of his own design. Johnson claimed that his device could generate motion from the use of rotor and stator magnets acting against each other. He further claimed that, with magnets made from the proper materials, the device could operate for over 18 years and only lose two percent of its magnetization. Little has been seen of Johnson’s device since the patent was granted.

“Yusmar 1,” a purported electrothermal water-based generator, was “invented” by Dr. Yuri Potapov in 1981. Under testing, the device failed to work.

In the 1990s, CETI claimed to have invented a device that would produce small amounts of heat via cold fusion. Skeptics noted that friction effects were likely the actual heat source. No further developments have since been claimed.

2001-Present: Bearden, GWE & Steorn

Tom Bearden claimed to have created an motionless electric generator in 2001. Bearden maintained that his device could sustain its operation and power an additional load without external electrical power. Allegedly, the generator extracted vacuum energy from the surrounding environment. A US Patent was granted in 2002, despite widespread skepticism. The American Physics Society issued a formal statement against the granting of the patent, leading the US Patent and Trademark Office to reexamine, and later revoke, the patent.

Also in 2002, the Genesis World Energy group (GWE) claimed to have developed a device that could separate water into H2 and O2. Supposedly, the device used less energy that thought possible, though no independent confirmation was ever made. In 2006, GWE founder Patrick Kelly received a five-year prison sentence for stealing funds from investors.

Later in 2006, Steorn Ltd. began soliciting scientists to study a perpetual motion device based on rotating magnets. Jury investigations began in December of that year. “Technical difficulties” led to the cancellation of a public demonstration planned for July 4, 2007. In 2009, Steorn’s scientific jury determined that the company’s technology did not work.

Tesla Photo credit: San Diego Air & Space Museum Archives / Foter / No known copyright restrictions
Feynman Photo credit: Foter / Public Domain Mark 1.0

Important People, Important Discoveries, Technology, World-Changing Inventions

The Watt Steam Engine

Developed between 1763 and 1775, the Watt steam engine was an extension and improvement of the Newcomen engine. The Watt was the first steam engine to drive its piston via pressurized steam and a partial vacuum. James Watt’s design is considered a key step in the evolution of modern mechanical engines.

Improving the Newcomen Engine

Developed by Thomas Newcomen, the Newcomen engine was far superior to previous incarnations of the steam engine, offering significant improvements in efficiency. Older steam engine models consistently lost steam, and therefore power, at the end of each stroke.

The Newcomen engine’s “atmospheric” design used a cylinder with a movable piston connected by a chain to one end of a pivoting beam, which operated a mechanical pump at the opposite end. Steam entered the cylinder below the piston with each stroke, followed by water, which condensed the steam. As the upper end of the steam cylinder was open, this created a partial vacuum that drew the piston down and raised the far end of the beam.

After being tasked with repairing a Newcomen engine at the University of Glasgow in Scotland in 1763, Watt noticed its inefficiencies and saw room for improvement. Based on his observations, Watt made several changes to the Newcomen engine’s design.

A separate condenser outside of the steam cylinder itself condensed the steam without the need for water spray, which cooled the piston and cylinder walls, reducing efficiency. The two chambers were connected, allowing for condensation and power transfer without loss of heat—the condenser remained cool, while the steam cylinder stayed hot.

Watt sealed the top of the steam cylinder and devised a method of injecting low-pressure steam into the area above the piston. This boosted the vacuum and increased the power of the down stroke, which in turn improved the speed and efficiency of the engine.

Finally, adjusting the design to produce rotary motion, instead of the previous oscillating movement of the Newcomen, proved more useful for industrial applications.

A preserved/restored Watt steam engine.

A preserved/restored Watt steam engine.

The Boulton Partnership

Though his design was completed and he had built a functioning model (ca. 1774), Watt was unconvinced that a marketable version of his engine could be developed. Watt entering into a partnership with Matthew Boulton, a Birmingham entrepreneur. Boulton funded the development of a full-scale test engine, giving Watt access to the facilities, capital, and craftsmen needed to bring his vision to life.

Boulton and Watt went into business selling and installing the steam engines in mines, ironworks, and other industrial locations. The bulk of their profit, however, came from a licensing fee charged to all owners of the steam engines, based on the fuel savings they generated—a  Watt engine used only about one-quarter the fuel that a similarly-sized Newcomen engine would. Despite the licensing fees, this exceptional fuel efficiency made the Watt steam engine the far more attractive option for most businessmen.

Further Improvements

The first Watt steam engines used hammer iron cylinders, which were out of round and caused leakage in the piston. By 1776, an inventor named John Wilkinson had developed a boring machine that was able to produce cylinders up to 50 inches in diameter with perfect precision. The introduction of bored cylinders further improved the Watt engine’s performance.

With a special arrangement of valves, steam could be admitted to either end of the engine. This allowed the direction of the power stroke to be reversed, creating the world’s first double-acting steam engine. This development also improved the engine’s efficiency and speed, and produced a more regular, stable motion.

Using a unique four-bar linkage, coupled with a pantograph—a development Watt dubbed “parallel motion”—the chain that once connected the piston rod and the engine’s moving beam was replaced. This allowed the piston to both push and pull with equal force.

This, in turn, made it possible for the motion of the beam to turn a wheel. Watt’s first rotary motion solution connected the beam to a wheel by a crank—however, the use of the crank was patented, so another method had to be developed. Using an epicyclic sun and planet gear system, Watt created a unique solution. (Later, after the patent on the crank expired, Watt reverted to this more-effective method.)

To ensure that the turning wheel operated at a consistent speed, a steam regulator valve was attached to a centrifugal governor. Watt based this design on the automatic speed controls used on windmills of his day.


With these improvements, Watt’s steam engine became an effective and reliable replacement for the water wheels and (literal) horsepower that had, until that point, powered British industry. Because it significantly improve efficiency and removed the need for a source of flowing water, the Watt steam engine allowed for vast expansion of industry throughout the country and drove the Industrial Revolution to new heights.


Photo credit: Foter / Creative Commons Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0)