Who invented Pacemaker?

Wilson Greatbatch, 1946

The heart is essentially a muscle that serves as a pump, sending a pulse of blood into our arteries every second or so. Some heart problems can be traced to a faulty heartbeat. Nervous impulses, generated in a piece of heart tissue called the pacemaker, fail to drive the heart in a reliable rhythm. The solution is the artificial pacemaker, able to send regular pulses of electric current into the natural one if it is failing.

Why Pacemaker use in heart?

The idea of using electricity to shock the heart muscle back into regular action is an old one; 19^th century physicians tried to induce the needed currents from outside the body. The first to try this internally was probably Canadian engineer John Hopps, around 1941. Cables were run through the chest wall into the heart tissue, but the pulse was generated from outside from equipment the size of a modern TV, and the shocks delivered were painful.

The implantable artificial pacemaker, carried within the bodies of millions of people with troublesome hearts, was invented by American bioengineer Wilson Creatbatch around 1958. There was some serendipity. While building a device to record heart sounds, he stumbled upon a circuit that produces regular pulses like heartbeats. It was small enough to fit inside the patient’s chest. Having generated interest among heart surgeons, Greatbatch begin hand-crafting pacemakers. Once the pacemaker had been implanted, the user was soon unaware of its operation. Around 1970 Greatbatch matched his new device with a small lightweight lithium battery to power it, similar to the mobile phones and laptop batteries. With circuits driven by transistors, the pacemaker drew so little current that battery lasted for years.

Modern pacemakers have the added advantage of microprocessor control. They are able to respond more flexibly to changes in the heartbeat, including detecting and dealing with fibrillation or tachycardia, when the heart beats very fast and inefficiently. In 1983 the American National Society of Professional Engineers rated the pacemaker as one of the ten most important engineering contributions to human society in the previous 

Who invented Stethoscope?

Rene Laennec, 1816

The name ‘stethoscope’ comes from Greek words meaning ‘looking at the chest’, but the organs of ‘looking’ in this case are the ears. The name was given by its inventor, French doctor Rene Laennec. Various myths surround the discovery: that Laennec could not hear a patient’s heart because street urchins were making a racket outside, and/or that the urchins were scraping on one end of a wooden fence and listening to the sound at the other end.

Laennec gave his version of events in an article in 1821. His patient that day was a young woman with a diseased heart, but tapping on her chest provided no information due to, as he put it, ‘the great degree of fatness’. Her age and sex meant he could not put his ear directly to her chest.

Suddenly he recalled how the scratching of a pin on one end of piece of wood could be clearly heard by placing an ear to the other end. Laennec did not immediately search around for a piece of wood, but rather made tube from 20 sheets of paper. He placed one end of the tube on the fat girls chest, the other to his ear. ‘J’ender! (I hear!) he reputedly cried, as the sounds of her ailing heart reached him with unprecedented clarity.

Laennec treated patients with heart and lung diseases at the Necker Hospital in Paris. With his new device, he was soon able to develop new methods of diagnosis, ‘a set of new signs of diseases of the chest, for the most part, certain, simple and prominent’. It was a major step forward in medical practice.

Laennec experimented with various materials, seeking the best transmission of sound. Surprisingly, solid materials like glass, metals and wood did not work as well as the column of air in his paper tube, though he quickly moved to wooden tubes 30 centimeters long, turned (reportedly) on his own lathe, with one end flared out into a bell. Some decades later the availability of flexible rubber tubes allowed the development of a ‘twoered’ stethoscope, much as we have today.

Laennec himself died of consumption (TB) aged only 45, a decade after his great invention and six weeks after returning to his native Brittany.

Who invented Helicopter?

Igor Sikorsky, 1946

The idea for the helicopter supported and driven by large, rotating horizontal blades, was probably inspired by the spinning sails of a windmill. Instead of moving air pushing the sails around, the powered sails would push on the air. Later models had onboard clockwork motors, even steam engines.

History of Invention:

By the 19^th century ‘screw’ propellers were pushing ships and were used in early attempts at powered flight. But a practical load carrying helicopter came only in the mid 20^th century, mostly through Russian born engineer Igor Sikorsky. Son of a psychiatry professor and a doctor, Sikorsky’s early interest in aviation was stimulated by news of the Wright Brothers and Zeppelin airships. He became a major innovator, building the first ever multi-engine aircraft, promoting revolutionary ideas like all metal construction, enclosed cabins with upholstered chairs for passengers, even an onboard toilet.

Sikorsky had migrated to the USA after the Russian Revolution. In 1931 he returned to his early attempts at a helicopter, undertaken in 1909 aged only 20. The weight of engines kept his creation on the ground. The first real success with horizontally rotating blades came with the ‘autogyro’, devised by the Spaniard Juan de la Cievra in 1923. An ordinary airscrew pulled the plane forward, supported by large unpowered rotors spinning freely.

When more efficient light weight engines arrived, along with light, strong construction materials, a number of inventors began to experiment again, including the German Heinrich Foche. Sikorsky had the most success. To stop the whole machine turning in the opposite directions to the rotor, he added a second small rotor on the tail (other designers had used counter rotating blades). His prototype VS300 first flew in May 1940, with the designer at the controls. A year later, a production VS300 stayed aloft for 90 minutes. The largest R4 made the first ever helicopter rescue in Burma in 1944. Sikorsky,s single rotor machine remains the dominant design today.

Who invented Elevator?

Elisha Otis, 1853

Big cities today are dominated by tall buildings. About 125 years ago, the typical cityscape was very different; few buildings reached more than three or four stories, limited by building techniques, access and the provision of services.

Invention story:

Even then, numerous innovations were encouraging the upward urge Metal-frame construction, made possible by the new Bessemer steel and enhanced by Joseph Monier’s reinforced concrete meant that outer walls no longer carried the weight of a building. Water could be sent to the upper floors with powerful pumps driven by electric motors. Communication from the lowest floors to the highest was made easier by the telephone. Most significantly, the endless climbing of stairs was banished by Elisha Otis’s elevator.

Platforms pulled up and down on ropes had been carrying goods from floor to floor in warehouses for decades, but putting passengers in such lifts raised safety concerns. What if the rope broke? Otis, employed as a youth in a bed manufacturer’s warehouse, realized that a fail-safe lift needed some automatic, perhaps spring loaded, device that could snap into place if needed and lock the platform in the shaft.

In 1853 at the New York Crystal Palace Exhibition, standing several stories up on an open platform, he ordered his assistant to cut the rope supporting it. The watching crowd gasped, but Otis did not fall to his death. He stood on the unmoving platform, waving his top hat. It was a marketing triumph.

His safety elevator had lived up to its name. By 1873 more than 2000 Otis elevators were in place in office buildings, hotels, apartment blocks and department stores. In 1904 the Otis organization, run by his sons (Otis himself had died in relative obscurity in 1861), pioneered the high speed elevator that real skyscrapers needed.

The term ‘skyscraper’ had entered the language in the 1880s, when the tallest buildings were merely 20 stories; striking for the day, trivial now. The purpose in going up was of course, to make more efficient use of precious land space in cities, and to increase its value. The look of our cities changed forever.                

Who invented Credit Cards?

John Biggins, 1946

Today ‘plastic money’ or credit cards have transformed the handling of money, impacting retailing and personal finance heavily. The idea is at least a century old. In the 1890s in Europe, merchants began using cards to administer credit offered to valued customers. The practice gained popularity through the 1920s. Such ‘store cards’ did not involve the banks directly and could only be used at the issuing organizations, such as merchants, hotels chains or petrol retailers.

History of Invention:

John Biggins of the Flatbush National Bank is usually acknowledged as inventing the bank issued credit card in 1946. His ‘Charge-It’ system allowed merchants to bill the bank, the bank then debiting the account of the card user. The practice spread rapidly through the 1950s. Banks collaborated to develop the widely accepted cards now known as Visa (1966) and Master Cards (1967). In 1950 Diners club issued 200 customers with a card that could be used to pay bills at restaurants, with the customer later repaying Diners. American Express, already profiting from the issuing of travelers cheques, followed in 1958.

Further advances were sparked by new technology. The introduction of magnetic stripes on cards allowed them to stroe important identification details. IBM had pioneered this in the 1960s and they were first used to speed ticketing at airports. By the early 1970s, the used of magnetic stripes had been standardized, with resulting improvement in security and efficiency, all cards still have tem , though there is increasing use of embedded memory chips to supplement or replace the strip, as they hold much more information.

Rapidly advancing information technology has further boosted the credit card industry. Most credit card readers are now online, linked into central computers that can instantly check the customer’s status and issue approvals. Fraud has decreased, paperwork has been decimated. Debit cards and EFTPOS (electronic funds transfer at point of sale), available since the 1980s, allow people to use their own money for cashless purchases, with funds moved from their account to the merchants. We have not yet reached the long promised cashless society, but we have certainly moved a long way down that path.

Who invented Diesel Engine?

Rudolf Diesel, 1895

Rudolf Diesel remains well known today through the type of engine that bears his name, now widely used, and its distinctive fuel. Diesel should have made a fortune from his inventions, but had no head for business.

How Diesel Engine Invented?

Diesel trained as a refrigeration engineer in Munich; his exam results were the highest ever achieved. Steam engines, though much improved by James Watt and others, remained unacceptably inefficient, turning perhaps 15 percent of the energy in coal into useful work. They were also too big and costly. More efficient (therefore smaller) engines could power vehicles.

Etienne Lenoir and Nicolaus Otto had already created ‘internal combustion engines’ in which the fuel was burnt inside the cylinder rather than outside, as in a steam engine. Seeking greater efficiency in a ‘rational heat engine’, Diesel proposed injecting fuel into the cylinder and igniting it, not with a spark or flame, but by the high temperature generated as the piston compressed the air in the cylinder. By working through a much wider range of temperatures and pressures, his engines would exploit more of the energy of the burning fuel.

Diesel’s first engine, set running in 1893, was a failure. The intended fuel was coal dust; funding came from industry giants like steel magnate Baron von Krupp. The coal dust fuelled engine exploded during trials, nearly killing him.

A second model, also operational in 1893, used heavy fuel oil, less refined and therefore cheaper than petrol, his 1895 model had unprecedented fuel efficiency, opening up many applications. Diesel became famous. Within a few decades, diesel engines were powering factories, water pumps, automobiles and trains and ships.

Diesel engines have traditionally produced smoky exhaust fumes, posing risks to health and the environment, and poor acceleration, making them less popular than petrol engines. But more refined technology, especially in fuel injection, and better quality fuels have largely solved these problems, letting the inherent benefits of Rudolph Diesel’s creation shine through.

Who invented X-rays?

Wilhelm Rontgen, 1895

Who invented X-rays? In the late 19^th century, German physicist Wilhelm Rontgen was interested in the newly discovered ‘cathode rays’ which were generated when high-voltage electricity was passed between two electrodes inside a glass tube almost empty of air. It would soon be shown that cathode rays were streams of tiny fragments of electric charge to be called ‘electrons’, the same particles that had caused the Edison Effect. The phenomenon would give rise in due course to television and other uses of the ‘cathode ray tube’.

Researchers had noted to their annoyance that photographic plates stored near such ‘discharge tubes’ were inexplicably fogged, as if they had been exposed to light. Rontgen wondered wondered if discharge tubes gave off invisible radiation, especially since the walls of the tubes glowed under the impact of the cathode rays. Perhaps the radiation could leak through the packaging surrounding photographic plates and expose them.

History of Invention:

In 1895, Rontgen found that radiation easily passed through a light proof shroud around the discharge tube, and made a plate covered with a fluorescent chemical glow several meters away. For something so unexpected and mysterious, the term X-rays seemed appropriate. They were also called Rontgen Rays for a time.

X-rays were stopped by a thin sheer of metal, but could cut through human tissue and emerge with enough energy to leave an image on a photographic plate. The first X-ray photograph’ ever taken was of Rontgen’s wife’s hand, clearly showing her bones and a ring surrounded by the shadow of her flesh.

Rontgen became famous winning the first Nobel Prize for Physics. He remained strikingly reticent and preferred to work alone, till he was taken by cancer at the age of 78.

Rontgen cannot be said to have ‘invented’ X-rays; they had always existed. But he did show how they might be used. X-ray images have proved of incomparable value to medicine and surgery and later to engineering and industry. More powerful and precise X-ray tubes were soon invented, particularly by the American William Coolidge from General Electric. The hazards of the technology, such as its capacity to cause cancer, were discovered only later.

Who invented Aspirin?

Felix Hoffman, 1899

Who invented Aspirin? The world’s most widely used medical drug is probably aspirin, known scientifically as acetylsalicylic acid. In an unrefined form, it was found in traditional portions made from the bark of the white willow tree (Salix Alba, hence the scientific name) and other plants. Aspirin is versatile. It reduces pain and lowers fever, particularly by affecting vital body chemicals called prostaglandins. In recent times aspirin has been found to thin the blood, reducing the risk of strokes and heart disease. In high doses it gives relief from arthritis.

History of Invention:

An early form of the drug, salicylic acid, was extracted from plants as the beginning of the 19^th century, but because of its severe side effects, little interest was shown until 1897, when Felix Hoffman and a colleague at the large German chemical firm Bayer discovered how to make acetylsalicylic acid, a form of the chemical that did not exist in nature and had fewer side effects. The first patient was Hoffman’s own father, who suffered severely from arthritis and could not tolerate straight salicylic acid.

Bayer patented the drug in 1899; the modern pharmaceutical industry was born. Although another company was already selling it, and a French chemist had devised a similar form 40 years earlier but Bayer was first to mass produce the drug. During world war- I various countries devised ways to make the drug synthetically, from the chemical phenol found in coal tar. In Australia, the result was called Aspro.

At the time aspirin came into use, the only other antipyretics (drugs to reduce fever) came from the bark of the cinchona tree, along with the anti-malarial quinine. Supplies of the bark ran short in the 1880s and the hunt was soon on for alternatives. This quickly led to the identification of the antipyretic phenacetin and then of paracetamol, though the latter’s importance was not recognized for half a century. Not until the 1950s was paracetamol on the market, known as Tylenol in the USA and Panadol in the UK, where it was at first available only on prescription.

Between them, aspirin and paracetamol have fixed a lot of headaches and high temperatures; our lives would have been very different without them.

Who invented Traffic Light?

Lester Wire, 1912

Who invented Traffic Light ? Traffic lights are a technology with many claims to paternity. If we mean the present red yellow green system, its first appearance was in New York in 1918 or perhaps Detroit in 1920. In all probability, it was in the USA and in response to the growing volumes of traffic as the factories of Henry Ford and others poured out cars cheap enough for the average person to buy.

Attempts to control traffic by signals dated back at least 50 years earlier to a signal post with movable arms like railway semaphores set up to outside parliament house in London in 1868. Red and green gas lamps provided warnings at night, although according to reports the signal blew up after a year of use, killing a policeman and discouraging further experiment.

History of Invention:

The first electric traffic signals, though with only red and green lights, were the work of Salt Lake City policeman Lester Wire in 1912. Placed in charge of the traffic squad, he sought to ease the chaos on the city roads caused by the increasing popularity of automobiles. He also wanted to save fellow policemen from standing in the rain to direct traffic.

Instead they could control the lights from a shelter nearby. Wire refined his system but never patented it, and died having received no royalties.

In 1923 Afro-American inventor and sewing machine repairman Garrett Morgan, patented a cheap and simple traffic control system, using hand- cranked movable arms. This became quite popular, and the myth grew that Morgan had invented traffic signals, which is clearly not so. The US patent office had issued 50 patents before his.

Early systems could be operated either automatically, the lights changing at set time intervals, or manually, controlled by a policeman able to view the state of the traffic and make appropriate adjustments. Not until the 1960s were electronic circuits inserted in the roads to monitor traffic flows, so that the cycling of the lights could be adjusted to minimize delays. From the 1980s, information technology allowed a variety of light change cycles to be applied at any particular intersection as traffic conditions changed, and the succession of lights down a stretch of road to be coordinated.

Who invented Laser?

Thomas Maiman, 1960

Who invented Laser ? Lasers are everywhere in modern technology. Yet initially they were just a laboratory curiosity, ‘a solution in search of a problem’. The first laser (an acronym for Light Amplification by the Stimulated Emission of Radiation) was built in 1960 by American Thomas Mainman, mostly to prove that it could be done. He used a rod of ruby, which sounds expensive and exotic, but lasers today use a wide range of solids, liquids and gases as the ‘medium’ to generate their unique radiation.

How it works ?

A laser’s talent lies in making the atoms or molecules in the medium behave in exactly the same way and at the same moment. When stimulated, all the particles release energy (in the form of light) simultaneously. Htat makes the light coherent, with the peaks and troughs of the light waves all lined up. And they all release precisely the same amount of energy, so that all the light is the one pure color. (The radiation can be invisible infrared or ultraviolet, rather than visible light, but the same properties apply.)

Coherent light has very little tendency to spread out, unlike the beam of a torch, and it can be focused into a very tight spot, less than a thousandth of a millimeter across. That makes lasers ideal for detecting the tiny marks that code information in the grooves of a CD or DVD. Tight focusing lets a laser deliver its energy into a tiny area, able, for example, to burn very tiny and perfectly formed holes in metal for precision engineering. Coherent light is also vital need in holography, a technology to give images a 3-D look.

The precise color of a laser beam means that many can be sent together down an optic fiber without confusion, greatly increasing the fiber’s capacity to carry data. It also let us measure distances with great accuracy, by timing how long a pulse of laser light takes to travel there and back. By bouncing laser beams off orbiting satellites, we know for sure that the continents are moving relative to each other at a few millimeters a year. Most likely, your builder or carpenter now uses a laser device to measure up the job.

All these are powerful applications. But in 1960, Maiman and his colleagues were not thinking about them. They just wanted the laser to work.

Who invented Bullet Train?

Hideo Shima, 1964

Who invented Bullet Train ? The first successful steam locomotive, George Stephenson’s Rocket, could manage 20 km an hour. Over the next 150 years steady if incremental improvements in engines, tracks and railway operations, saw speeds reach five or eight times that of the Rocket.

Only France and Japan were thinking seriously about new designs and systems that would go faster, Japans’s Shinkansen popularly called the Bullet Train because of its shape, began running between Tokyo and Osaka in 1964, in time for the Tokyo Olympics, Seventeen years later, but still well ahead of anyone else, the first French TGV began plying between Paris and Lyon.

History of Bullet Train:

Not everything about these trains was new. The newly built rolling stock was streamlined to cut wind resistance, but was still powered by electricity from overhead wires, and still carried by steel wheels on steel rails over conventional (if often newly laid) track bed. The French Japanese were simply pushing the existing technology as far as it would go.

The speeds were impressive, averaging over 250 km per hour over a journey of several hours, and reaching over 500 km per hour in trials. Travel was comfortable, departures punctual, environmental consequences minimal and the safety record impressive, especially once the tracks were fenced off. Similar train lines began to appear in other countries, and the lines could compete with air travel over short distances, being cheaper, taking less time and consuming less energy.

Was that enough? Some thought not and were already experimenting with the next generation technology, a major leap toward magnetic levitation or ‘mag-lev’. No longer would trains run on rails. They would float above them, held up, guided and even driven forward by the interaction of electromagnetic fields between the track and the train. With no motors, the trains would be much lighter and more economical to run. No ‘mag-lev’ train is yet in service, but the Japanese active since 1970, have reached nearly 600 km per hour in trials. Even higher speeds, approaching 1000 km per hour, would be possible with the train running through an evacuated tube.

Who invented Digital Camera?

Steven Sasson, 1975

The history of photography goes back about 200 years. The many generations of cameras all had one thing in common: images were recorded on glass plates or plastic film using chemical emulsions that were sensitive to light. They were made visible and permanent by chemical processing. Other than the briefly successful Polaroid process no camera took a picture you could look at immediately. Furthermore, the only way you could send a good quality photo to someone was as a hard copy printed on paper.

The comparison with today’s electronic or digital cameras is startling. You can view the image as soon as you have snapped it, and you can send it down a phone line or cable, confident it will arrive looking good. And processing is easy. You can play with images, enlarge them, change the framing or color balance; things that previously look hours in the dark room.

History of invention:

This world of digital imaging is very new, for the everyday photographer at least. The first affordable electronic cameras reached the market only in the early 1990s. Their origins lay a few decades further back, and derive much from the development of television. That, too, required technology to convert images into electric currents. In most digital cameras, the key component is the CCD based like the computer chip on semiconductors such as silicon. A CCD is an array of light sensitive cells that accumulate electric charge in proportion to the brightness of the light that falls on them, much as solar cells do. The level of charge on the pixels can be read out one by one, the data stored and processed to recreate the scene.

The first CCDs, built in the 1970s, were crude; with only 10000 pixels (modern cameras boast millions of pixels). The images were correspondingly fuzzy. The first attempt to build one of these into a camera, undertaken by Steven Sasson at Eastman-Kodak in 1973, was equally clunky. The camera weighed 4 kg and took 20 seconds per image. It was only a technical exercise to see if it could be done, not intended for the market.

But the exercise began an inevitable trend, one that will ultimately kill off the business that Kodak pioneered cameras using film. Such cameras are not yet dead, but they live on mostly in one niche, as the cheap, disposable cameras of last resort, used in emergencies or extreme environments such as underwater. These cameras trade off cost and disposability against image quality and just about every other feature of both traditional and digital photography. It is a rather sad farewell.

The evolution of the digital camera has been swift, in line with the rest of information technology. We see the same trends: ever increasing capabilities at ever decreasing cost. Early digital cameras cost $ 10000 or more; that price has shrunk at least 20-fold. Progress has been aided by the development of international standards for storing images in digital code, such as the JPEG format devised by the joint Photography Expert Group. Among other things, this allows images to be ‘compressed’. A great deal of information in an images to be ‘compressed. A great deal of information in an image can be discarded without unacceptable loss of quality, as with DVDs and MP3 players. As a result, images take up much less space in computer memories and can be quickly transmitted by email or over the Internet.

New sorts of data storage, such as ‘flash memory’, let a camera store more pictures, Inkjet printer generate quality copies on demand. Cameras continue to get smaller, now often barely larger than a credit card, able to be secreted in a mobile phone or in hard to reach places. Similar technology has transformed video cameras. Most electronic cameras will now take both still and moving pictures. We have come a very long way in little more than a decade.

The digital camera transformation raises a host of issues. Simplicity and ubiquity (such as in mobile phones) have encouraged some inappropriate use, with invasions of privacy that can verge on assault. The capacity to manipulate images by digitally altering the location and content of individual pixels has damaged our confidence that ‘the camera never lies’. Surveillance in public places is easier and cheaper and therefore more common. This no doubt helps with the maintenance of law and order but asks a question about our right to privacy once we step out of our front doors. Digital cameras are one of the ways we can create and access information freely for ourselves, a capacity central to the information age, open to both use and abuse.

Who invented Electricity?

Michael Faraday, Joseph Henry, 1853

Many see Michael Faraday, the bookbinder’s apprentice (and protégé of Humphry Davy) who rose to head London’s Royal Institution, as the greatest researcher of the 19^th century, or perhaps ever. His reputation rests mostly on his prodigious studies of electricity and magnetism over a period of 20 years.

History of Electricity:

He knew of the link the Dane Hans Orsted had found between electricity and magnetism. An electric current in wire is surrounded by magnetic field. In 1831 he asked ‘if electricity can produce magnetism, can magnetism produce electricity?. Anyone can do what he did. He wrapped a wire a number of times around one side of an iron ring, and connected the ends to a battery and switch. He wrapped a second coil around the other side of the ring and connected it to an instrument to report any current that flowed. He hoped to show that a current flowing in one coil would make the current flow in the other, the connection coming via the magnetic field.

Almost nothing happened. When Faraday turned on the current in the first coil, the needle in the galvanometer flicked quickly one way before settling back to zero. When he turned the current off again, the needle flicked the other way and returned to zero. So the magnetic field had to be changing, growing stronger or weaker, before it would make a current flow.

Faraday had found ‘electromagnetic induction’. A changing magnetic field ‘induces’ a current in a nearby wire. The practical consequences were obvious. A machine with magnets and coils of wire constantly moving relative to each other would produce a sustained electric current, as an alternative to using a battery. Faraday’s first ‘dynamo’ spun a copper plate between the poles on a powerful magnet. A current flowed in the disc but energy wastage was high. Still the crucial principle had been demonstrated.

A year later French inventor Hippolyte Pixii replaced the disc with some coils of wire, holding them still and spinning the magnet. This began decades of research to find the best arrangement of coils and magnets, including electromagnets, to convert movement into electricity. Some designs produced a current in only one direction (direct current or DC); other designs produced alternating current (AC), which flowed back and forth.

Similar findings were being made across the Atlantic. Natural philosopher Joseph Henry was a major figure in the growth of American science in the 19^th century, with achievements as both a researcher and a statesman of science. In 1846 he left a post at what was later called Princeton University to become the first Secretary of the newly founded Smithsonian Institution in Washington, today one of the world’s great museums and laboratories in science and technology. He also helped found the National Academy of Science, the North American equivalent of the Royal Society.

These roles took him away from his own research but his reputation was already secure, particularly in electricity and magnetism. In the late 1820s he built on the discovery of electromagnetism and made powerful electromagnets by wrapping thousands of loops of current carrying wire around iron bars. Some of these powered the first electric telegraph in America which among other benefits allowed the rapid reporting of weather information and forecasts; Henry was instrumental in setting up a national system for the purpose.

Working independently, Henry built electric motors and discovered electromagnetic induction in the same year as Faraday. He took the matter further, discovering ‘self induction’ before Faraday did. Changing current in a coil of wire makes a changing magnetic field; that field in turn generates another current in the same coil opposing the first. So changing currents (including alternating ones) are impeded or ‘choked’ as they try to pass through a coil of wire. The more rapidly the current changes the more noticeable the effect. ‘Chokes’ or ‘inductors’ remain vital components of electronic circuits today. Henry’s contribution is commemorated in the unit of inductance: the henry.

Faraday and Henry both grasped the use of induction in a ‘transformer’. If two coils are wound on the same piece of iron, the first with a few turns of wire, the second with many, the induced current in the second coil has a much higher ‘voltage’ than the first. So voltages can be ‘stepped up’ but only with alternating currents (AC); steady ‘direct’ current in the first; otherwise energy would be created. Raising the voltage lowers the current, and vice versa, an important consideration in the later ‘Battle of the Current’ as the use of electricity began to spread.

Who invented Potato chip?

George Crum, Herman Lay, 1853

When it comes to popular snacks, the potato chip or ‘crisp, must be up there with the leaders, Thomas Jefferson, later president of the USA, came to enjoy the French style while on duty as ambassador there in the late 18^th century. He bought the recipe home and served the thick cut fried potato slices (not today’s meaning of ‘French fries’) to his guests.

History of Potato chips:

In 1853 Native American chef George Crum had French fried potatoes on the menu at the Sun Moon restaurant at the expensive Saratoga Springs resort in upstate New York. But one diner, reputedly the millionaire banker and New York social icon Cornelius Vanderbilt, did not care for them. Too thick, he declared, and sent them back. Crum prepared a second, thinner serving but the guest was still not satisfied Irate, Crum cut them so fine they went cristp when fried, too thin and hard to be speared with a fork. He expected the diners to be angry, but they were delighted. Proclaiming the browned, paper-thin tidbits delicious, they demanded more.

Crum was onto a winner. He made his invention a speciality of the house, calling them ‘potato crunches’. He was soon packaging them for sale as Saratoga Chips.

Some distance remained to be covered before this New England dinner-time delicacy could be counted a global gastronomic phenomenon. There key events all occurred in the 1920s: the invention of machines to peel and slice the potatoes, previously done laboriously by hand; the first use of waxed paper bags to keep the crisps crisp (plastic film not het being available); and the intervention of Herman Lay. A travelling salesman from the north, he peddled potato chips to storekeepers throughout the American south from the boot of his car. He built a business that linked his name indelibly with the salty snacks, especially once he merged his company with Firto, a Dallas based firm that made corn chips. Frito-Lay is the largest maker of potato chips in the USA and therefore on the planet.

Who invented Bicycles?

Pierre Michaux, 1861

Why did the invention of the bicycle take so long? For 5000 years, wheels had been used in various combinations, including two side by side. But no one had put two wheels in one line and sat between them until the Frenchman de Sivrac around 1690. Yet it did not take off. For one thing, de Sivrac could not steer his machine.

History of Bicycles:

Around 1816 the German inventor Karl Drais marketed his’ running machine’ or ‘Draisine’ often dubbed a ‘hobbyhorse’. Steerable, it had no pedals; the rider had to propel the machine by kicking the ground on either side. It was not a comfortable ride; the wooden wheels had iron rims.

In 1839 the Scotsman Kirkpatrick Macmillan connected the back wheel to pedals with crank, and a rider could easily move faster than they could walk. But the bicycle boom did not come until the French carriage maker Pierre Michaux, asked to repair a Draisine, proposed a pair of pedals fixed to the front wheel, producing the ‘velocipede’. That was 1861.

The machine moved forward by only the circumference of the front wheel at every turn of the pedals, so manufacturers mad the front wheel larger and larger, producing the ‘Penny-farthing’. With a very large wheel, the rider perched on top and a small trailing wheel for balance, these were easy to ride, but tumbles were common. Thomas Stevens rode such a bicycle across the USA.

The propulsion breakthrough also came in the 1880s, with the first ‘bicycle chain’ with metal links to drive the back wheel from pedals. Different sized gearwheels had the back wheel running faster than the pedals; a ‘freewheeling’ mechanism let the rider stop peddling without stopping moving.

With the addition of inflatable rubber tyres in 1888, ball bearings to reduce friction in the works and many experiments with the form of the steel tubes- bicycles such as John Stanley’s Rover gained the form we see today, and unprecedented popularity. People now had the speed and freedom of movement they once had riding horses, till bicycles were overtaken, by the next big thing in personal transport, the automobile.