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The process

1

Hydrogen gas enters the fuel cell on the anode side, where the electrochemical potential pulls it through the catalyst

2

When hydrogen molecules come in contact with the platinum on the catalyst, they split into two protons (H+ ions) and two electrons (e-).

3

Meanwhile, on the cathode side of the fuel cell, oxygen gas is being forced through the catalyst, where it forms two oxygen atoms. These atoms have a strong negative charge, which pulls the two hydrogen protons through the exchange membrane.

4

The electrons simultaneously travel through the anode and make their way through an external circuit generating electricity, eventually returning to the cathode side of the fuel cell.

Fuel Cell Module

All these reactions occur in a cell stack. Cell stacks are contained within a larger system that includes fuel, water and air management, coolant control, hardware, and software. The systems vary in size and use according to their different applications, from transportation to industrial machinery to backup power that can supplement the electric grid.

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The process Hydrogen gas enters the fuel cell on the anode side, where the electrochemical potential pulls it through the catalyst When hydrogen molecules come in contact with the platinum on the catalyst, they split into two protons (H+ ions) and two electrons (e-).

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SPOTLIGHT STORY

Meet the man behind the Mac

Today we're celebrating the 250th birthday of Scottish inventor Charles Macintosh, the creator of the famous 'Mackintosh' raincoat!

Scroll on to meet the man and his iconic creation...

Who was Charles Macintosh?
Charles Macintosh was born in Scotland on December 29, 1766.

At the beginning of his career, Macintosh worked as a clerk for a Glasgow merchant, but by the age of 19 he had already given it up to pursue his true passion: chemistry. At 20 years old Macintosh opened up his own plant in Glasgow that worked on innovative new dying methods. While experimenting with the chemical naphtha (an oily liquid by-product of tar), Macintosh stumbled across something that would change how we dress - and relate to our environment - forever.

In 1823 Macintosh patented his new process. By sandwiching a layer of liquid rubber (made with naphtha) between two layers of fabric, Macintosh had created a new material that would be resistant to water while also remaining flexible and wearable. Resistant to wet and rainy conditions, the new fabric was perfect for making coats.

The Mac was born!

How did the coat take off?
Although today the Mackintosh coat (the 'k' of 'Mackintosh' has been added over the years) may be a timeless classic, when it was first sold it was a technological breakthrough.

In the early 19th Century, when the synthetic fibers we have come to rely upon weren't available, the water proofing of clothes was a continual struggle. When Charles Macintosh patented his superior method of rubberising fabric he created a new product that became an instant success.

Early Mac coats had problems with smell, stiffness, and a tendency to melt in hot weather, but these were largely solved by the patenting of a new innovation: the vulcanising of rubber in 1843. Although Charles Macintosh's process wasn't perfect, and would steadily be improved over time, it was far superior to any other product on the market. The Mackintosh coat became ubiquitous and its name came to define an entire category of clothes.

How is a Mac made?
Mackintosh still produce coats with a surprisingly simple process that uses the same technology as the original Mackintosh coat.

The core material in a Mackintosh coat is still the bonded cotton that is made using a process originally patented by the company founder Charles Macintosh in 1823. This cotton is now produced by Mackintosh in Japan before being delivered to its factory in Cumbernauld, Scotland.

Once the bonded cotton arrives at the Mackintosh factory, a cutter, using an agreed pattern, will cut out each individual piece ready for them to be sewn and glued together.

Each seam is glued and taped by hand. As well as ensuring that the seams of each coat are waterproof, this technique makes it easier to join both curved edges and corners. All the seams are stitched and then each seam has the rubber-based glue applied then rolled to make it flat.

The blobs of glue are tight and rubbery and skillfully applied by the worker's finger. When the solution on the coat is dry, any excess can be removed by roller and brush.

Each finished Mackintosh coat will have been hand cut, glued and sewn in the same factory in Scotland. Skilled Scottish craftsmen and women use techniques that have remained largely unchanged for almost 200 years since Macintosh's original process.

Why is it important?
The Mackintosh coat is an icon of British fashion. The first Mackintosh coat was sold in 1823 and since then the Mackintosh has come to define classic British style for close to 200 years. Throughout this time Mackintosh has been a part of British life; clothing not only the most elegant but also providing waterproof and durable clothing to the British Army and Police. Today Mackintosh still makes clothes in Britain but its popularity has become truly global. From humble beginnings in 1823, the Mackintosh has become known the world over.

Thanks Charles Macintosh, for keeping us warm and dry for over 200 years!

Learn more about the Mackintosh coat in this British Fashion Council exhibit.

Share this story with a friend

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Charles Macintosh and his Famous Coat - Google Arts & Culture

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SPOTLIGHT STORY Meet the man behind the Mac Today we're celebrating the 250th birthday of Scottish inventor Charles Macintosh, the creator of the famous 'Mackintosh' raincoat! Scroll on to meet the man and his iconic creation... Who was Charles Macintosh? Charles Macintosh was born in Scotland on December 29, 1766.

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Electromagnet invented 1825 by William Sturgeon
In 1825, Lancastrian electrician, William Sturgeon, revealed his invention of the electromagnet. This enabled electrical energy to be used in the design of controllable machinery. Sturgeon was an amazing man
He had a difficult start to life, his mother died when he was quite young and his father sent him away to become apprenticed to a boot maker. Life didn't become much easier when he joined the army.

He was sent to the Royal Artillery base in Woolwich and married a widow who kept a local shoe menders. But sadness followed him and all three of his children and his wife died. He immersed himself in self education, teaching himself mathematics and a range of languages including Greek. He also studied science and philosophy and honed his practical mechanical skills.

The army sent him to Newfoundland and whilst there observed many thunderstorms which inspired a fascination with electricity.

Although he left the army, William Sturgeon had made connections with many people who thought like him, the Greenwich Royal Observatory was only a stones throw away and the Royal Military Academy trained the Royal Artillery and the Royal Engineers.

Electromagnetism, discovered by Hans Christian Oersted, was already well known about and William Sturgeon became very interested in it's effects.

In 1824 he was appointed lecturer in Science and Philosophy at the East India Royal Military College and lecturer in science at the Royal Military College and by 1825 was able to show his first working electromagnet but he didn't stop there. In 1832 he built an electric motor and invented the commutator, an integral part of most modern electric motors. He lectured at the Adelaide gallery for practical science, patronized by people such as Thomas Telford. He also invented the first suspended coil galvanometer, a device for measuring current. As a result of his work, the American inventor, Joseph Henry, produced a far more powerful magnet which led to the development of an electronic communication system, the telegraph.
William Sturgeon died in 1850 in Prestwich Lancashire.

The mixing of scientific talents at clubs and galleries such as the Adelaide, helped to promote a general interest in sciences and Sturgeon was keen that science and entertainment should go hand in hand to bring it to the general public

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Electromagnet Invented 1825 by William Sturgeon

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In 1825, Lancastrian electrician, William Sturgeon, revealed his invention of the electromagnet. This enabled electrical energy to be used in the design of controllable machinery. Sturgeon was an amazing man He had a difficult start to life, his mother died when he was quite young and his father sent him away to become apprenticed to a boot maker.

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Henry Cort (1740-1800) was an English ironmaster. During the Industrial Revolution in England, Cort began refining iron from pig iron to wrought iro...

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Spinning mule: Spinning mule, Multiple-spindle spinning machine invented by Samuel Crompton (1779), which permitted large-scale manufacture of high-quality thread for the textile industry. Crompton's machine made it possible for a single operator to work more than 1,000 spindles simultaneously, and was capable of

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Lombe's Silk Throwing Mill: The First Factory : HistoryofInformation.com

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"Little of the original mill remain. It is known from written sources that it was five storeys high rectangular in plan. It was built of brick, in flemish bond, being 33.5m long by 12m wide. It was built on a series of stone arches that allowed the waters of the River Derwent to flow through.

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Batteries are a common source of power in our present age. We use batteries to start our cars, to power our laptops, to allow us to talk on our cell phones for hours and even to propel some of our electric vehicles for miles and miles on a single charge. They can range from sizes smaller than a pencil eraser to as large as 2,000 square meters (21,528 square feet). The largest battery in the world has the capacity to power the entire town of Fairbanks, Alaska, a city of about 12,000 people, for up to seven minutes in an emergency situation [source: Conway].

Some of the first primitive types of batteries can be traced all the way back to the Parthians around 250 B.C. when the they lived in the area of modern day Baghdad [source: Buchmann]. The Parthians made a clay jar, filled it with vinegar, then put a copper cylinder inside of it with an iron rod sticking out of the top. This early type of battery was used to electroplate silver.

But it wasn't until the late 1700s that scientists began conduct more serious experiments on electricity and its storage. Experiments were conducted that stored electricity or produced it, but none were able to create a continuous and controllable current of electricity. That is, not until the Italian physicist Alessandro Volta came along. In 1800, Volta created the first modern day battery when he built what came to be known as his voltaic pile. The pile was made of up of zinc and copper plates with vinegar- or brine-dampened pieces of leather or pasteboard placed in between each plate. The plates were then stacked in alternating order one on top of the other with the bottom plate and the top plate acting as the positive and negative terminals.

The pile looked like a stack of coins and created a constant flow of electricity that was less intense than previous attempts and allowed scientists to use electricity in controlled ways. A year after Volta first introduced his voltaic pile he presented his invention to the French National Institute, in which Napoleon Bonaparte was in attendance. In honor of Volta's invention, his name is used as the unit of electromotive measurement known as a volt.

For more information about batteries and other inventions, follow the links on the next page.

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Batteries are a common source of power in our present age. We use batteries to start our cars, to power our laptops, to allow us to talk on our cell phones for hours and even to propel some of our electric vehicles for miles and miles on a single charge.

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Portland Cement and the invention of concrete

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Portland Cement and the invention of concrete

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Throughout history, cementing materials have played a vital role and were used widely in the ancient world. The Egyptians used calcined gypsum as a cement and the Greeks and Romans used lime made by heating limestone and added sand to make mortar, with coarser stones for concrete.

The Romans found that a cement could be made which set under water and this was used for the construction of harbours. This cement was made by adding crushed volcanic ash to lime and was later called a "pozzolanic" cement, named after the village of Pozzuoli near Vesuvius.

In places where volcanic ash was scarce, such as Britain, crushed brick or tile was used instead. The Romans were therefore probably the first to manipulate systematically the properties of cementitious materials for specific applications and situations.

Roman contribution to cement technology

Marcus Vitruvius Pollio, a Roman architect and engineer in the 1st century BCE wrote his "Ten books of Architecture" - a revealing historical insight into ancient technology. Writing about concrete floors, for example:

"First I shall begin with the concrete flooring, which is the most important of the polished finishings, observing that great pains and the utmost precaution must be taken to ensure its durability".

"On this, lay the nucleus, consisting of pounded tile mixed with lime in the proportions of three parts to one, and forming a layer not less than six digits thick."

And on pozzolana:

"There is also a kind of powder from which natural causes produces astonishing results. This substance, when mixed with lime and rubble, not only lends strength to buildings of other kinds, but even when piers are constructed of it in the sea, they set hard under water."

(Vitruvius, "The Ten Books of Architecture," Dover Publications, 1960.)

His "Ten books of Architecture" are a real historical gem bringing together history and technology. Anyone wishing to follow his instructions might first need to find a thousand or so slaves to dig, saw, pound and polish...

After the Romans, there was a general loss in building skills in Europe, particularly with regard to cement. Mortars hardened mainly by carbonation of lime, a slow process. The use of pozzolana was rediscovered in the late Middle Ages.

The great mediaeval cathedrals, such as Durham, Lincoln and Rochester in England and Chartres and Rheims in France, were clearly built by highly skilled masons. Despite this, it would probably be fair to say they did not have the technology to manipulate the properties of cementitious materials in the way the Romans had done a thousand years earlier.

Cement history and the Industrial Revolution

The Renaissance and Age of Enlightenment brought new ways of thinking which led to the industrial revolution. In eighteenth century Britain, the interests of industry and empire coincided, with the need to build lighthouses on exposed rocks to prevent shipping losses. The constant loss of merchant ships and warships drove cement technology forwards.﻿﻿

﻿Smeaton, building the third Eddystone lighthouse (1759) off the coast of Cornwall in Southwestern England, found that a mix of lime, clay and crushed slag from iron-making produced a mortar which hardened under water. Joseph Aspdin took out a patent in 1824 for "Portland Cement," a material he produced by firing finely-ground clay and limestone until the limestone was calcined. He called it Portland Cement because the concrete made from it looked like Portland stone, a widely-used building stone in England.

While history usually regards Aspdin as the inventor of Portland cement, Aspdin's cement was not produced at a high-enough temperature to be the real forerunner of modern Portland ﻿cement. Nevertheless, his was a major innovation and subsequent progress could be viewed as mere development.

A ship carrying barrels of Aspdin's cement sank off the Isle of Sheppey in Kent, England, and the barrels of set cement, minus the wooden staves, were later incorporated into a pub in Sheerness and are still there now. Those who wish can sup a pint and contemplate cement history!

A few years later, in 1845, Isaac Johnson made the first modern Portland Cement by firing a mixture of chalk and clay at much higher temperatures, similar to those used today. At these temperatures (1400C-1500C), clinkering occurs and minerals form which are very reactive and more strongly cementitious.

While Johnson used the same materials to make Portland cement as we use now, three important developments in the manufacturing process lead to modern Portland cement:

Development of rotary kilns

Addition of gypsum to control setting

Use of ball mills to grind clinker and raw materials

From the turn of the 20th century, rotary cement kilns gradually replaced the original vertical shaft kilns, used originally for making lime. Rotary kilns heat the clinker mainly by radiative heat transfer and this is more efficient at higher temperatures, enabling higher burning temperatures to be achieved. Also, because the clinker is constantly moving within the kiln, a fairly uniform clinkering temperature is achieved in the hottest part of the kiln, the burning zone.

The two other principal technical developments, gypsum addition to control setting and the use of ball mills to grind the clinker, were also introduced at around the start of the 20th century.﻿﻿﻿﻿

An entire web﻿site could easily be devoted to the history of cement, but this brief introduction may suffice to place cement in a historical context.

Check Out the Understanding Cement Resources!

We have some great training and reference resources. Some are free and some are paid-for.

The paid-for resources are unique to Understanding Cement and proceeds from these sales contribute to the costs of operating and developing this website - see our bookstore here.

The free resources are available on the Cembytes Resources Page. Currently, they include:

Ebook: "Low Concrete Strength? Ten Potential Cement-Related Causes": this illustrated ebook is a checklist of some of the main causes of cement-related low strength in concrete or mortar.

Cement glossary: glossary of over 100 cement-related definitions and chemical formulae.

Screensaver/desktop images: s ix microscope images of clinker and concrete that you can use as desktop/tablet or screensaver images, or anything else you want.

Subscribers to Cembytes, our free Understanding Cement Newsletter, can download these free resources from the Cembytes Resources Page.

If you are not already a subscriber, just sign up using the box below and you can be downloading the ebook, glossary and photos within a minute or two. Make sure you bookmark the resources page so you can get back to it later - there are no links to it from the website navigation as it is for Cembytes subscribers only!

If you are already a subscriber to Cembytes, you can access the Cembytes Resources Page directly if you have bookmarked it. However, if you have forgotten how to reach the Resources page, you can easily get back to it. Just enter your email in the signup box below and if you are on the subscriber list you will see a link to the Resources Page.
(Note: we currently have two Cembytes subscriber lists, and old one and a new one, and we are gradually transferring to the new one. Depending when you subscribed, you will be on one list or the other. If you are on the old list, the signup box won't recognize you because it is only connected to the new list, but that's fine. Just confirm your subscription and you will be on the new list. After you confirm you will receive an email with a link to the Resources Page.)
Get a Better Understanding of Cement

Articles like this one can provide a lot of useful material. However, reading an article or two is not really the best way to get a clear picture of a complex material like cement. To get a more complete and integrated understanding of cement and concrete, do have a look at the Understanding Cement book or ebook.

This easy-to-read and concise book contains much more detail on concrete chemistry and deleterious processes in concrete compared with the website.

For example, it has about two-and-a-half times as much on ASR, one-and-a-half times as much on sulfate attack and nearly three times as much on carbonation. It has sections on alkali-carbonate reaction, frost (freeze-thaw) damage, steel corrosion, leaching and efflorescence on masonry. It also has about four-and-a-half times as much on cement hydration (comparisons based on word count).

Check the Article Directory for more articles on this or related topics

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Throughout history, cementing materials have played a vital role and were used widely in the ancient world. The Egyptians used calcined gypsum as a cement and the Greeks and Romans used lime made by heating limestone and added sand to make mortar, with coarser stones for concrete.

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Early Forms of Long-Distance Communication

Before the development of the electric telegraph in the 19th century revolutionized how information was transmitted across long distances, ancient civilizations such as those in China, Egypt and Greece used drumbeats, signal fires or smoke signals to exchange information between far-flung points.

However, such methods were limited by the weather and the need for an uninterrupted line of sight between receptor points. These limitations also lessened the effectiveness of the semaphore, a modern precursor to the electric telegraph. Developed in the early 1790s, the semaphore consisted of a series of hilltop stations that each had large movable arms to signal letters and numbers and two telescopes with which to see the other stations.

Like ancient smoke signals, the semaphore was susceptible to weather and other factors that hindered visibility. A different method of transmitting information was needed to make regular and reliable long-distance communication workable.

Did you know? SOS, the internationally recognized distress signal, does not stand for any particular words. Instead, the letters were chosen because they are easy to transmit in Morse code: "S" is three dots, and "O" is three dashes.

The Electric Telegraph

In the early 19th century, two developments in the field of electricity opened the door to the production of the electric telegraph. First, in 1800, the Italian physicist Alessandro Volta invented the battery, which reliably stored an electric current and allowed the current to be used in a controlled environment.

Second, in 1820, the Danish physicist Hans Christian Oersted demonstrated the connection between electricity and magnetism by deflecting a magnetic needle with an electric current.

Samuel Morse

While scientists and inventors across the world began experimenting with batteries and the principles of electromagnetism to develop some kind of communication system, the credit for inventing the telegraph generally falls to two sets of researchers: William Cooke and Charles Wheatstone in England, and Samuel Morse, Leonard Gale and Alfred Vail in the United States.

In the 1830s, the British team of Cooke and Wheatstone developed a telegraph system with five magnetic needles that could be pointed around a panel of letters and numbers by using an electric current. Their system was soon being used for railroad signaling in Britain.

During this time period, the Massachusetts-born, Yale-educated Morse (who began his career as a painter), worked to develop an electric telegraph of his own. He reportedly had become intrigued with the idea after hearing a conversation about electromagnetism while sailing from Europe to America in the early 1830s, and later learned more about the topic from American physicist Joseph Henry.

In collaboration with Gale and Vail, Morse eventually produced a single-circuit telegraph that worked by pushing the operator key down to complete the electric circuit of the battery. This action sent the electric signal across a wire to a receiver at the other end. All the system needed was a key, a battery, wire and a receiver.

Morse Code

To transmit messages across telegraph wires, in the 1830s Morse and Vail created what came to be known as Morse code. The code assigned letters in the alphabet and numbers a set of dots (short marks) and dashes (long marks) based on the frequency of use; letters used often (such as "E") got a simple code, while those used infrequently (such as "Q") got a longer and more complex code.

Initially, the code, when transmitted over the telegraph system, was rendered as marks on a piece of paper that the telegraph operator would then translate back into English. Rather quickly, however, it became apparent that the operators were able to hear and understand the code just by listening to the clicking of the receiver, so the paper was replaced by a receiver that created more pronounced beeping sounds.

Western Union

In 1843, Morse and Vail received funding from the U.S. Congress to set up and test their telegraph system between Washington, D.C., and Baltimore, Maryland. On May 24, 1844, Morse sent Vail the historic first message: "What hath God wrought!" The telegraph system subsequently spread across America and the world, aided by further innovations.

Among these improvements was the invention of good insulation for telegraph wires. The man behind this innovation was Ezra Cornell, one of the founders of the university in New York that bears his name. Another improvement, by the famed inventor Thomas Edison in 1874, was the Quadruplex system, which allowed for four messages to be transmitted simultaneously using the same wire.

Use of the telegraph was quickly accepted by people eager for a faster and easier way of sending and receiving information. However, widespread and successful use of the device required a unified system of telegraph stations among which information could be transmitted.

The Western Union Telegraphy Company, founded in 1856 in part by Cornell, was at first only one of many such companies that developed around the new medium during the 1850s. By 1861, however, Western Union had laid the first transcontinental telegraph line, making it the first nationwide telegraph company.

Rise and Decline of the Telegraph System

Telegraph systems, a key innovation during the Industrial Revolution, soon spread across the world. Extensive systems appeared across Europe by the later part of the 19th century, and by 1866 the first permanent telegraph cable had been successfully laid across the Atlantic Ocean; there were 40 such telegraph lines across the Atlantic by 1940.

The electric telegraph transformed how wars were fought, how money was sent and how newspapers conducted business. Rather than taking weeks to be delivered by horse-and-carriage mail carts, pieces of news could be exchanged between telegraph stations almost instantly. The telegraph also had a profound economic effect, allowing money to be "wired" across great distances.

Telegrams, often delivered to homes and businesses by delivery boys, were a popular way of communicating during the 1920s and 1930s, when long-distance calls were more expensive than a telegram. Western Union was famous for messages hand-delivered inside its signature yellow envelopes.

By the end of the 19th century, however, new technologies such as the telephone began to emerge. In time, these technologies would overshadow the telegraph, which would fall out of regular widespread usage.

In 2006, Western Union officially ended its telegram service after 150 years. Although the telegraph has since been replaced by the even more convenient telephone, fax machine and Internet, it laid the groundwork for the communications revolution that led to those later innovations.

Sources

Invention of the Telegraph. Library of Congress.
A History of Telegraphy. Pens.co.uk.
Telegram Passes Into History. Wired Magazine.

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Morse Code & Telegraph: Invention & Samuel Morse - HISTORY

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The telegraph and Morse code revolutionized long-distance communication after their invention in the 1800s by Samuel Morse and other inventors.

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Interchangeable Parts - Inventions - HISTORY.com

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Find out more about the history of Interchangeable Parts, including videos, interesting articles, pictures, historical features and more. Get all the facts on HISTORY.com

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Bessemer process, the first method discovered for mass-producing steel. Though named after Sir Henry Bessemer of England, the process evolved from the contributions of many investigators before it could be used on a broad commercial basis. It was apparently conceived independently and almost concurrently by Bessemer and by William Kelly of the United States. As early as 1847, Kelly, a businessman-scientist of Pittsburgh, began experiments aimed at developing a revolutionary means of removing impurities from pig iron by an air blast. Kelly theorized that not only would the air, injected into the molten iron, supply oxygen to react with the impurities, converting them into oxides separable as slag, but that the heat evolved in these reactions would increase the temperature of the mass, keeping it from solidifying during the operation. After several failures, he succeeded in proving his theory and rapidly producing steel ingots.

In 1856 Bessemer, working independently in Sheffield, developed and patented the same process. Whereas Kelly had been unable to perfect the process owing to a lack of financial resources, Bessemer was able to develop it into a commercial success. Another Englishman, Robert Forester Mushet, found that adding an alloy of carbon, manganese, and iron after the air-blowing was complete restored the carbon content of the steel while neutralizing the effect of remaining impurities, notably sulfur. A Swedish ironmaster, Goran Goransson, redesigned the Bessemer furnace, or converter, making it reliable in performance. The end result was a means of mass-producing steel. The resultant volume of low-cost steel in Britain and the United States soon revolutionized building construction and provided steel to replace iron in railroad rails and many other uses.

The Bessemer converter is a cylindrical steel pot approximately 6 metres (20 feet) high, originally lined with a siliceous refractory. Air is blown in through openings (tuyeres) near the bottom, creating oxides of silicon and manganese, which become part of the slag, and of carbon, which are carried out in the stream of air. Within a few minutes an ingot of steel can be produced, ready for the forge or rolling mill.

The original Bessemer converter was not effective in removing the phosphorus present in sizable amounts in most British and European iron ore. The invention in England, by Sidney Gilchrist Thomas, of what is now called the Thomas-Gilchrist converter, which was lined with a basic material such as burned limestone rather than an (acid) siliceous material, overcame this problem. Another drawback to Bessemer steel, its retention of a small percentage of nitrogen from the air blow, was not corrected until the 1950s. The open-hearth process, which was developed in the 1860s, did not suffer from this difficulty, and it eventually outstripped the Bessemer process to become the dominant steelmaking process until the mid-20th century. The open-hearth process was in turn replaced by the basic oxygen process, which is actually an extension and refinement of the Bessemer process.

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Bessemer process | Dates, Definition, & Facts

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Bessemer process, the first method discovered for mass-producing steel. Though named after Sir Henry Bessemer of England, the process evolved from the contributions of many investigators before it could be used on a broad commercial basis. It was apparently conceived independently and almost concurrently by Bessemer and by William Kelly of the United States.

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This article was most recently revised and updated by

flying shuttle, Machine that represented an important step toward automatic weaving. It was invented by John Kay in 1733. In previous looms, the shuttle was thrown, or passed, through the threads by hand, and wide fabrics required two weavers seated side by side passing the shuttle between them. Kay mounted his shuttle on wheels in a track and used paddles to shoot the shuttle from side to side when the weaver jerked a cord. Using the flying shuttle, one weaver could weave fabrics of any width more quickly than two could before.

Robert Curley.

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Flying shuttle | Weaving, Textiles, Loom

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Flying shuttle, Machine that represented an important step toward automatic weaving. It was invented by John Kay in 1733. In previous looms, the shuttle was thrown, or passed, through the threads by hand, and wide fabrics required two weavers seated side by side passing the shuttle between them.

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Read the essential details about the Water Frame. The Spinning-Frame was too large to be operated by hand and so Richard Arkwright had to find another method of working his machine. After experimenting with horses, Arkwright decided to employ the power of the water-wheel. Arkwright's machine now became known as the Water-Frame.

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Home > Learning >History >Timelines: Sources from History >Accessible version > The Spinning Jenny

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steam engine, machine using steam power to perform mechanical work through the agency of heat.
(Read James Watt's 1819 Britannica essay on the steam engine.)
A brief treatment of steam engines follows. For full treatment of steam power and production and of steam engines and turbines, see Energy Conversion: Steam engines.

In a steam engine, hot steam, usually supplied by a boiler, expands under pressure, and part of the heat energy is converted into work. The remainder of the heat may be allowed to escape, or, for maximum engine efficiency, the steam may be condensed in a separate apparatus, a condenser, at comparatively low temperature and pressure. For high efficiency, the steam must fall through a wide temperature range as a consequence of its expansion within the engine. The most efficient performance-that is, the greatest output of work in relation to the heat supplied-is secured by using a low condenser temperature and a high boiler pressure. The steam may be further heated by passing it through a superheater on its way from the boiler to the engine. A common superheater is a group of parallel pipes with their surfaces exposed to the hot gases in the boiler furnace. By means of superheaters, the steam may be heated beyond the temperature at which it is produced by boiling water.

In a reciprocating engine, the piston and cylinder type of steam engine, steam under pressure is admitted into the cylinder by a valve mechanism. As the steam expands, it pushes the piston, which is usually connected to a crank on a flywheel to produce rotary motion. In the double-acting engine, steam from the boiler is admitted alternately to each side of the piston. In a simple steam engine, expansion of the steam takes place in only one cylinder, whereas in the compound engine there are two or more cylinders of increasing size for greater expansion of the steam and higher efficiency; the first and smallest piston is operated by the initial high-pressure steam and the second by the lower-pressure steam exhausted from the first.

In the steam turbine, steam is discharged at high velocity through nozzles and then flows through a series of stationary and moving blades, causing a rotor to move at high speeds. Steam turbines are more compact and usually permit higher temperatures and greater expansion ratios than reciprocating steam engines. The turbine is the universal means used to generate large quantities of electric power with steam.

The earliest steam engines were the scientific novelties of Hero of Alexandria in the 1st century ce, such as the aeolipile, but not until the 17th century were attempts made to harness steam for practical purposes. In 1698 Thomas Savery patented a pump with hand-operated valves to raise water from mines by suction produced by condensing steam. In about 1712 another Englishman, Thomas Newcomen, developed a more efficient steam engine with a piston separating the condensing steam from the water. In 1765 James Watt greatly improved the Newcomen engine by adding a separate condenser to avoid heating and cooling the cylinder with each stroke. Watt then developed a new engine that rotated a shaft instead of providing the simple up-and-down motion of the pump, and he added many other improvements to produce a practical power plant.

A cumbersome steam carriage for roads was built in France by Nicholas-Joseph Cugnot as early as 1769. Richard Trevithick in England was the first to use a steam carriage on a railway; in 1803 he built a steam locomotive that in February 1804 made a successful run on a horsecar route in Wales. The adaptation of the steam engine to railways became a commercial success with the Rocket of English engineer George Stephenson in 1829. The first practical steamboat was the tug Charlotte Dundas, built by William Symington and tried in the Forth and Clyde Canal, Scotland, in 1802. Robert Fulton applied the steam engine to a passenger boat in the United States in 1807.

Though the steam engine gave way to the internal-combustion engine as a means of vehicle propulsion, interest in it revived in the second half of the 20th century because of increasing air-pollution problems caused by the burning of fossil fuels in internal-combustion engines.

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Steam engine | Definition, History, Impact, & Facts

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Steam engine, machine using steam power to perform mechanical work through the agency of heat. In a steam engine, hot steam, usually supplied by a boiler, expands under pressure, and part of the heat energy is converted into work. Learn more about steam engines in this article.