Historical Science & Technology

Pont du Gard: Aqueduct Yeah!

Constructed of shelly limestone, the Pont du Gard is an ancient Roman aqueduct that is still standing today, crossing the Gardon River in southern France. Built circa 40 CE, the three-tiered bridge was added to the list of UNESCO World Heritage Sites in 1985.

Slap On Some Aqueduct Tape & Call It A Day

Details are understandably a little spotty roughly 2,000 years later, but the architect of the Pont du Gard is generally credited as Marcus Vipsanius “Big Marc” Agrippa, son-in-law and stooge of Emperor Augustus. Agrippa was the senior magistrate responsible for the water supply to Rome and its many colonies. Historians estimate that construction of the bridge took about 15 years and employed roughly 800 to 1,000 workers.

The Pont du Gard today. Well, not today today, but y'know, recently.

The Pont du Gard today. Well, not today today, but y’know, recently.

As the Roman Empire slowly fell apart, so did the Pont du Gard. From the 4th Century CE onward, maintenance of the aqueduct was neglected—invading forces and local uprisings kept Roman forces plenty busy. Debris, plant roots, and mineral deposits combined to create deposits up to 20 inches thick on each wall. At its peak, the Pont du Gard carried an estimated 44 million gallons of water a day to the citizens of Nîmes, but this flow had slowed considerably by the 6th Century CE and the aqueduct fell out of use.

The Pont du Gard continued to serve as a toll bridge for centuries, however. In the 13th Century CE, the King o’ France gave locals the right to collect tolls from those using the bridge, with the caveat that these same locals were in charge of maintaining the bridge.

Three centuries later, lead Huguenot Henri, Duke of Rohan (“Big Hank”) and his traveling soldiers caused significant damage to the bridge when they hauled their artillery across it on their way to battle against French royalists. To fit his carts and cannons through the bridge’s narrow spaces, he had one side of the second level of arches cut away to only a third of their original thickness. Unsurprisingly, this severely compromised the Pont du Gard’s structural integrity.

Restoration efforts began in 1703, commissioned by local authorities, but by 1835 the bridge had deteriorated so badly that it was nearing collapse. Napoleon III visited the site in 1850, and set architect Charles “Big Chuck” Laisné to the task of repairing it, with funds provided by the Ministry of State. Following further restoration efforts, the most recent of which concluded in 2000 CE, it continued to be used as a footbridge across the Gardon.

A Marvel of Engineering

The Pont du Gard’s highest tier stands over 160 feet above the surface of the Gardon River. The upper deck of the three-level structure descends only about one inch from one side to the other, showing the exceptional precision of which Roman engineers were capable, despite the limited technology of the time.

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Pseudoscience

The Continuous Failure of Perpetual Motion

Like the philosopher’s stone and the perfect Cuban sandwich, the secret of perpetual motion has long been sought by mankind. Over the centuries, brilliant scientists and average Joes alike have tried—and failed—to create perpetual motion machines. We know today that the laws of thermodynamics make perpetual motion literally impossible, but earlier peoples had no such knowledge. Below are brief tales of some of history’s most significant “perpetual motion machines”.

Science?

Science?

The Magic Wheel

In 8th century CE Bavaria, a device known as the “magic wheel” was created; its “inventor” is lost to history. It was simply a wagon wheel on an axle, affixed to a base, and, once set in motion, the magic wheel would continue to spin for a very, very long time (though not perpetually). Locals at the time, being superstitious folk, thought the wheel was spun by magic. Instead, a series of large magnets around the wheel’s outer rim and a larger stationary magnet on the wheel’s base generated magnetic attraction and repulsion that kept the wheel in motion. Eventually, the wheel would come to a stop due to frictional losses at its central bearing, but it could spin for long enough to freak people out.

Indian mathematician and astronomer Bhāskara II created a thematically similar device, cleverly dubbed Bhāskara’s wheel. Instead of magnets, Bhāskara’s device used the flow of mercury between curved/tilted spokes to generate movement once set in motion. It, too, would eventually stop due to friction.

Maricourt’s Armillary Sphere

In the 13th century CE, French scholar and scientist Petrus Peregrinus de Maricourt—who is also known as Peter Maricourt and is somehow not a Harry Potter character—created a magnetically powered, “automatic” armillary sphere. Based on a design sketch of a perpetual motion machine by Villard de Honnecourt, Maricourt’s armillary sphere was designed to rotate perpetually on its celestial axis, once per day, to mimic the movement of the heavens above.

Cox’s Timepiece

In the late 18th century, James “Big Jim” Cox of jolly ol’ England and John Joseph “Big John Joe” Merlin of Belgium developed “Cox’s Timepiece.” The device operate in essentially the same way as any other mechanical clock of the time, but needed no winding. Cox claimed that it was a perpetual motion machine, and indeed the timepiece did work continuously without any outside intervention. However, as its internal mechanisms are powered by changes in atmospheric pressure via a mercury barometer, this is not true perpetual motion.

Cox’s timepiece still exists, and can be seen at the Victoria and Albert Museum in London. It no longer functions, however, as it was deactivated prior to being moved to the museum.

Sir Congreve’s Water Machine

In Eighteen-Hundred and Twenty-Seven, English inventor Sir William “Big Bill” Congreve created a convoluted contraption that utilized an endless band of sponge, a separate but equally endless band of weights, a bed of still water, and an inclined plane over pulleys. The sponge would raise water via capillary action, and the bands would turn as the weight of the water exceeded that of the weights, which would in turn squeeze the water out of the sponge as it rotated. This design allowed water to disobey the law of physics that prevents liquids from rising above their own level, which crated a continuous ascent and overflow. Though in theory his design was sound, it proved to be yet another failure in the pursuit of perpetual motion.

Keely’s Fraud

American inventor John Ernst “Big John Ernst” Worrell Keely announced the invention of an induction resonance motion motor, based on “etheric technology”, which even in 1872 must have sounded less than legit. Keely claimed that he had discovered a method of power generation based on the vibrations of tuning forks, and his machine appeared to run on water. Less than a year later, investors in Keely’s machine—who had given him nearly $5 million—accused the inventor of fraud, though no definitive proof was found at the time. After Keely’s death, it was discovered that his machine was powered by hidden air pressure tubes.

Perrigo’s Free Energy Device

In the late 1910s, MIT graduate and Missourian Harry Perrigo claimed to have invented a free energy device that derived its power from “thin air” or “aether waves”. Perrigo successfully demonstrated his device before Congress in December 1917, and had applied for a patent. However, investigators discovered that the device was powered by a hidden, battery-powered motor.

Papp’s Inert Gas Engine

In 1966, Joseph “Big Joe” Papp claimed to have invented an alternative internal combustion engine that ran on inert gases. He was awarded a patent for his perpetual motion device, as well as several others for unrelated inventions. Financial backing for production of his engine was secured from numerous investors, but a public demonstration of his engine resulted in an explosion that killed one observer and injured two others. Noted theoretical physicist Richard Feynman, who was critical of the abstracts of Papp’s patents, noting a poor grasp of theoretic physics and was present at the demonstration, concluded that the explosion was deliberate, an attempt by Papp to avoid the discovery of his hoax; Papp subsequently blamed the explosion on sabotage by Feynman. Papp continued to accept money from investors, but never produced or demonstrated another of his engines.

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Historical Science & Technology, World-Changing Inventions

The Wheel Deal

Though history will ultimately show that the distinction belongs to the toaster oven, the wheel is often regarded as mankind’s greatest invention. If nothing else, the device paved the way for most other major inventions, making it the Citizen Kane of human mechanical innovations.

And, like that interminably boring yet highly influential film, the wheel seems like it’s just been around forever—never really invented, just a part of the fabric of the world since time immemorial. But deep down inside, you know it wasn’t just magically birthed upon the Earth—it had to come from somewhere. Here’s the skinny on how the wheel came to be.

Step 1: Wheel; Step 2: ???; Step 3: Fortune

Agriculture and pottery, two industries that can benefit greatly from the use of wheels, were “invented” during the Aceramic Neolithic period (circa 9500 to 6500 BCE). However, the wheel itself was not actually developed until several thousand years later, during the late Neolithic, roughly 4500 to 3300 BCE. The invention of the wheel is considered one of the leading factors leading to the rise of the Bronze Age.

wheel

Early precursors to the potter’s wheel were developed in the Middle East in the 5th millennium BCE. However, these stone or clay wheels were not true, free-spinning potter’s wheels and required considerable effort to turn. The earliest evidence of a true potter’s wheel comes from Mesopotamia circa 4000 BCE; the oldest surviving example has been dated to roughly 3100 BCE.

The earliest evidence of wheels being used for vehicles comes from the latter end of the 4th millennium BCE. Wheeled vehicles were developed nigh simultaneously by the Sumerian culture in Mesopotamia, the Maykop culture of northern Caucasus, and the Cucuteni-Trypillian culture of central Europe. The oldest surviving example of a wheel-and-axle vehicle comes from Stare Gmaine, in Slovenia; it is dated to roughly 3340 BCE.

The earliest visual depictions of wheeled vehicles come from the Halaf culture, circa 6500 BCE, but as there is no evidence of Halafians actually using wheeled vehicles, it’s probably just the result of some hippie painter getting a little crazy with the ol’ artistic license.

Roll Out

Certain evidence suggests that the Ancient Chinese developed wheeled vehicles as early as 2000 BCE. There is definitive evidence of the wheel’s use in China circa 1200 BCE, when the chariot was introduced to the region.

The oldest surviving evidence of the wheel in Britain was discovered in early 2016. A large, wooden wheel measuring roughly one meter in diameter was discovered at the Must Farm archaeological site in East Anglia, and has been dated to roughly 1100 BCE. Additional artefacts uncovered near the wheel, including a hub and a horse’s spine, suggest that the wheel was part of a horse-drawn cart. Who knew horses were into art?

Though the Olmecs and other Ancient American cultures developed wheel-like implements for children’s toys and other small-scale uses (historical examples date to roughly 1500 BCE), they did not use “full size” wheels for carts or other transportation uses. The prevailing theory as to why these cultures didn’t use wheeled vehicles is that they had no domesticated animals large or strong enough to pull carts. The only options were bison, which are notoriously difficult to domesticate, and llamas, which were not really used outside of the Andes Mountains.

Beginning in approximately 400 BCE, potter’s wheels and water wheels were used extensively in the Nubian region of Ancient Africa. Horse drawn chariots, an innovation derived from the Egyptians, were also common. Outside of Nubia, Ethiopia, and Somalia, the wheel was little used in Africa until its “introduction” by Europeans in the 19th century CE.

Construction & Variations

The earliest wheels were wooden discs with holes in them for axles to pass through. Early man quickly discovered that a single horizontal slice of a tree is unsuitable for use as a wheel, as it lacks the appropriate structural strength; instead, longitudinally-derived boards were rounded out to form circles.

These early wheels generally fell into one of two types during the Neolithic period: “circumalpine,” in which the wheel and axle rotate together; and “Baden,” in which the axle remains stationary. Spoked wheels were invented more recently (circa 2000 BCE), and allowed for lighter and faster vehicles. Spoked-wheel war chariots were developed shortly after; iron-rimmed wheels were introduced by the Celts during the first millennium BCE.

From there, very little variation, modification, or innovation occurred until the late 19th century CE, when wire-spoked wheels and pneumatic tires were developed.

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Technology, World-Changing Inventions

You Down with PTFE?

Good ol’ polytetrafluoroethylene. It’s just the best, amirite? All right, good talk. See ya next time…

 

 

 

 

 

 

 

 

 

 

 

 

 

…Wait, hold on. Yeah, so polytetrafluoroethylene, a synthetic fluoropolymer of tetrafluoroethylene (don’t even get me started on that $#!t) is better known as PTFE, and even better known as Teflon®. But, because Teflon® is a registered trademark of DuPont Co. (hence the ®), and, like Band-Aids, pretty much became the everyday name for what it is, and because we hate when that kind of bulljazz happens (lookin’ at you, too, Jell-O), we’ll just keep on referring to it as PTFE.

Yeah, You Know Me

You know PTFE quite well, even if you’re unaware of it. It’s main application is as the non-stick coating on cooking pans and the like. Because it’s so slippery, it’s also used as a coating on catheters. Hopefully you’ve only experienced it when cooking and not whilst in the hospital.

Legend has it that PTFE was invented by accident. Back in 1938 CE, Roy “Big Roy” Plunkett was working at a DuPont lab in New Joisey, Whilst attempting to create a new type of refrigerant, his pressurized bottle of tetrafluoroethylene gas malfunctioned and stopped flowing before it was empty. Curious as to the cause of the failure, Plunkett eventually cut the tank in half and discovered that its interior was coated with a waxy, whitish, extremely slippery substance. A high pressure chemical reaction had caused the gas to react with iron from the inside of the bottle, creating polymerized perfluoroethylene.

This is your brain on PTFE. (Or brains, maybe? Not sure of the egg-to-brain ratio. I assume it's 1:1...?)

This is your brain on PTFE. (Or brains, maybe? Not sure of the egg-to-brain ratio. I assume it’s 1:1, so yeah, that would be brainS. Right…?)

After further R&D, the resulting PTFE material was patented in 1941; the name “Teflon®” was trademarked in 1945. By 1948, as part of a joint venture with General Motors, DuPont was cranking out more than two million pounds of their patented PTFE substance. One of its earliest uses was coating pipe valves and seals that held the uranium hexafluoride used in the Manhattan Project. The first PTFE-coated cooking pan, “The Happy Pan,” was first sold commercially in 1961.

PTFE PTFToday

PTFE is still most commonly used on cookware; however, it has found countless other uses since its debut. It is used to waterproof material for camping equipment like tents and rain jackets, and is often used as a spray-on stain repellent for high end fabrics.

Powdered PTFE is used in infrared decoy flares and rocket fuel igniters. In its solid form, the material can be used to make a wide range of products and parts. Though difficult, PTFE machining can produce strong but lightweight parts in almost any shape, form, or size.

Perhaps the best use PTFE was ever put to was as the inflatable roof of the Hubert H. Humphrey Metrodome in Minneapolis, Minnesota. But that’s a technological tale of terror for another time, Timothy.

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Technology

Blind Rivet McTell

Rivets have been around for literally 10,000 years. Okay, not literally literally, but y’know… they’ve been a thing for quite a while. These permanent mechanical fasteners are so popular that you’ve probably got a few examples on your person right now and didn’t even notice. (I am, of course, referring to the rivets in your blued jeans). But not all rivets are quite so famous. Here, we present the story of these devices’ vision-impaired variation—the blind rivet.

Once You Pop, You Can’t Stop

Blind rivets are often referred to as “pop rivets”, although that’s technically a brand name that eventually came to be synonymous with the thing that it is a brand of, like Band-Aids or Jell-O. They are tubular, with a mandrel through the center, and are installed by inserting the rivet into hole drilled through the parts it’s joining. Once in place, the end of the mandrel snaps off to leave a smooth surface. They are ideal for applications where the joint is only accessible from one side, making them “blind” from the opposite side.

Depending on what part of the country you're from, these might be "soda rivets." LOL JK.

Depending on what part of the country you’re from, these might be called “soda rivets.” LOL JK.

Few things come into this world fully-formed of course, and before becoming the beloved Stevie Wonder of the permanent mechanical fastener game, blind rivets went through a number of iterations. In 1916 CE, British engineer Hamilton Neil “Big Ham” Wylie” filed a patent for an “improved [method] of closing tubular rivets”; the patent was granted in May of the following year.

Five years later, Wylie became an advisor for Armstrong-Whitworth Ltd., a British aircraft manufacturer. In this role, Big Ham worked on metal construction techniques and continued to develop his rivet design, gaining a second patent in 1927. His new patent-worthy innovation incorporated the pull-through mandrel that allowed his rivets to be used “blind.”

A year later, the George Tucker Eyelet company introduced its “cup” rivet, a blatant rip off Wylie’s blind rivet that required a special mandrel and had to be assembled by hand. The Tucker company and Armstrong-Whitworth soon joined forces, and a modified, hybrid design was developed. The new blind rivet model was a one-piece unit that included both the mandrel and the rivet itself.

Shortly thereafter, aluminum versions of the new blind rivet were introduced, and trademarked under the name Pop rivets.

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