How does an MRI work?

How Does an MRI Work



Invention of MRI or magnetic resonance imaging was a revolution in medical diagnosis. This technique of imaging used in diagnosis of various ailments is based on the principles of nuclear magnetic resonance (NMR). It may all sound complicated, but with a little bit of interest, you will realize how an MRI machine generates images of our body.






MRI or magnetic resonance imaging, is a medical imaging technique, which facilitates detailed visualization of the internal structure of our body. It also helps in assessing some functions of the body to a certain extent. The technology, which was introduced in the last quarter of the 20th century, has undergone a dramatic change and gained immense popularity in the field of medicine today. The huge machine referred to as an MRI scanner is an object of fascination for many individuals, who are often left wondering how it works.






The Components of an MRI Machine






Before we move on to the working mechanism of MRI (Magnetic Resonance Imaging), let's take a brief look at the various components of the MRI scanner. The major components of an MRI machine include the primary magnet and the gradient magnets. The primary magnet, made from an electrical coil with power running through it, develops a magnetic field of around 1.5 to 3 Tesla. The gradient magnets, which are much smaller than the primary magnet, help in altering the magnetic field precisely. Other than these, the MRI scanner also includes the horizontal tube, wherein the person is made to lie for examination, and last, but the most important - the computer software and hardware components, which help in setting the parameters prior to the examination, and collecting the data in the form of multiple images.






How Does an MRI Scanner Work?






The MRI scanner is a giant cube, with a horizontal tube attached to it. The patient to be examined is made to lie on his back on this horizontal tube, and then, he is slowly slid into the machine. Whether the entire body of the individual will be sent in or just half of it, depends on which part of the body is to be examined. In case of brain MRI scan, sliding the upper torso of the patient inside the scanner would be enough for the diagnosis. As soon as the body part to be scanned reaches at the isocenter of the magnetic field, the scan begins.






How Does an MRI Generate Images of the Body?






A large part of the human body is composed of water molecules, each of which contains two hydrogen nuclei (or protons). When the patient is sent inside the scanner, the 'magnetic moments' of the protons present in the body align with the direction of the magnetic field. A radio frequency electromagnetic field is turned on for a few seconds, which makes the protons change their alignment relative to the field. As soon as the electromagnetic field is turned off, the protons return to their original alignment. The alterations in the alignment creates a signal which is detected by the scanner. The strength of the magnetic field determines the frequency at which the protons resonate.






Additional magnetic fields are created using the gradient magnets to determine the position of the protons, and the energy released by them. The damaged tissues can be detected as they take time in returning to the state of equilibrium. The parameters are set using the computer and contrast is created between different types of tissues. MRI with contrast is carried out by injecting contrast agents in the body, in order to enhance the appearance of the blood vessels, and to detect tumors and inflammation in the body. The computer takes a note of protons and the energy released by them to generate the image of the body part being examined.






Although MRI can be used to image any part of the body, it is most often used in neurological examinations, checking for tumors, abnormalities in blood vessels etc. MRI scan cost depends on which part of the body is being examined. A safe procedure owing to the exclusion of ionizing radiation, MRI has gained wide popularity in the medical field, across the world.

THE Girl who Excelled in EXCEL

Rebecca Rickwood (15) from Stilton, and attends Sawtry College, recently won a Microsoft Excel world championship in San Diego, and is the best in the world in her category. She also won $5000 USD as part of her prNext year, the 2012 Worldwide Competition on Microsoft Office will be held in Las Vegas, Nevada, USA







Teenage computer whizz Rebecca Rickwood showed she can excel in Excel after winning a worldwide championship.


Talented Rebecca, of Caldecote Road, in Stilton, near Peterborough, has taken home the title of World Champion in Microsoft Excel from the competition in San Diego, in the USA.


To scoop the crown, the 15-year-old beat more than 228,000 students from 57 countries around the globe in a hard fought contest of skill, determination and speed.


A thrilled Rebecca, who is a pupil at Sawtry Community College, had travelled across the Atlantic last Saturday and said she was delighted just to take part in the event.


But after knuckling down to take part on Monday, she then found out on Tuesday she had won, before returning home yesterday with the title and $5,000 prize.


She said: “I took the exams and entered the competition but I didn’t think about it.


“I was so shocked to hear that I had won and was going to San Diego for the finals.


“I’m really excited. I really didn’t think I would win. When I was waiting with all the other students to hear the result I was really nervous.


“I heard my name read out in first place and I just couldn’t believe it. I’m ecstatic, I can’t believe I won and now I’m world champion. It’s a day I’ll never forget.”


She travelled to the US with parents Adam and Tracy (both 46) and brother Matthew (13), who are delighted with her win.


Rebecca added: “We had a good time out there. We didn’t get to see much of San Diego itself, but it was still really good.


“My friends and family are all very happy for me.”


Rebecca had earned her right to attend the world finals in May after she achieved the top nationwide score in the Microsoft Office Specialist Excel certification exam.


She sat the exam at college and since then, she has continued to hone her skills by studying at lunch and in the evenings at her school, supported by teacher Pam Kitchen.


She said: “I’m absolutely delighted for Rebecca.


“She really is a wonderful student who is extremely talented but, also, a very modest person.


“What was most impressive was her hard work and dedication during lunchtimes and after school. We told her to go out to San Diego and be herself and are obviously thrilled to have her coming back to us as world champion.”


Kevin Ryan, marketing manager with Prodigy Learning, who are responsible for the competition in the UK, said: “We realised Rebecca was extremely talented and one to watch from her scores in the UK championships in May.


“But the world competition is another level; it’s highly competitive and notoriously difficult to win, particularly for someone so young.


“Rebecca really has done her country proud. I believe she has a very bright future ahead indeed.”


FACTFILE on... Rebecca’s triumph


THIS year was the 10th annual Worldwide Competition on Microsoft Office.


It features the Microsoft Excel 2007 category, won by Rebecca, but also in Microsoft Word 2010, Microsoft Excel 2010, Microsoft Word 2007 and Microsoft PowerPoint 2007.


It aims to show a student’s ability in the programme with Rebecca tested on formulas, formatting, databases and speed in Excel.

A collection of interesting facts regarding inventions.

– that a workman who left the soap mixing machine on too long was responsible for making Ivory Soap? He was so embarrassed by his mistake that he threw the mess in a stream. Imagine his dismay when the evidence of his error floated to the surface! Result: Ivory soap, the soap that floats.







– that the Band-Aid® Bandage was invented by a Johnson & Johnson employee whose wife had cut herself? Earl Dickson’s wife was rather accident prone, so he set out to develop a bandage that she could apply without help. He placed a small piece of gauze in the center of a small piece of surgical tape, and what we know today as the Band-Aid bandage was born!






– that the inventor of the World Wide Web, British-born Tim Berners-Lee, never made money on his invention, which revolutionized the computer world? In 1989 he envisioned a way to link documents on the Internet using “hypertext” so “surfers” could jump from one document to another through highlighted words. Berners-Lee decided not to patent his technology since he feared that, if he did patent it, use of the Web would be too expensive and would therefore not become used worldwide. He therefore passed up a fortune so the world could learn and communicate.






– that Robert Adler has the dubious distinction of being the Father of the Couch Potato? Back in 1955 Adler was employed by what was then Zenith Radio Corp., where he was charged to invent something that would allow viewers to turn down the TV volume without leaving their chairs. After a series of flops (such as a wired contraption that people tripped over), Adler hit on the idea of using sound waves. Thus the Remote Control was born . . . and some viewers haven’t moved since!






– that in 1879 Auguste Bartholdi received a design patent for the Statue of Liberty?






– that Galileo invented the thermometer in 1593?






– that the first ballpoint pen was invented by Hungarian journalist Lasalo Biro and his chemist brother, Georg, in 1938?






– that power steering was invented by independent inventor Francis W. Davis? As chief engineer in the 1920s of the truck division of the Pierce Arrow Motor Car Company, he saw how hard it was to steer heavy vehicles. So that he would be able to keep the profits from his future invention, Davis left his job, rented a small engineering shop in Waltham, Mass., and developed a hydraulic power steering system that led to power steering.






– that it was melting ice cream that inspired the invention of the outboard motor? It was a lovely August day and Ole Evinrude was rowing his boat to his favorite island picnic spot. As he rowed, he watched his ice cream melt and wished he had a faster way to get to the island. At that moment the idea for the outboard motor was born!






– that two musicians were responsible for the invention of color print film? Fascinated by photography, Leopold Godowsky and Leopold Mannes worked together to produce an easy-to-use, practical color film. They worked full time as music teachers and gave concerts while experimenting during their off hours in Mannes’ kitchen. Their success earned them full-time, well-paying jobs at Kodak and their efforts resulted in Kodachrome film, which was introduced in 1935.






– that the telescope was accidentally discovered in 1698 when Dutch eye glass maker Hans Lippershey looked through two lenses – one held in front of the other – and realized that the image was magnified?






– that one person who claimed to be the inventor of the television is Russian emigre Vladimir Zworykin? In 1929 David Sarnoff, founder of RCA, asked Zworykin what it would take to develop TV for commercial use. He said: a year and a half and $100,000. In reality, it took 20 years and $50 million! Before his death in 1982 at the age of 92, Zworykin said of his invention: “The technique is wonderful. It is beyond my expectations. But the programs! I would never let my children even come close to this thing.”






– that the formulas for Cola-Cola and Silly Putty have never been patented? These trade secrets are shared only with selected trustworthy company employees, and while there have been many attempts to duplicate these products, so far, no one has been successful.






– that Benjamin Franklin invented bifocals because he hated wearing two pairs of glasses?






– that several people are credited with the invention of the flush toilet? Most people have heard of Thomas Crapper (1837-1910), the sanitary engineer who invented the valve-and-siphon arrangement that made the modern toilet possible. Another claimant to “the throne” was British inventor Alexander Cumming who patented a toilet in 1775. Then there’s a nameless Minoan (a native of ancient Crete) who lived 4,000 years ago who supposedly was ahead of his time and created the first flush toilet!






– that after Parker Brothers executives turned down the game of Monopoly because it had “52 fundamental errors” (including taking too long to play), a copy of the game wound up in the home of the company president who stayed up until 1 a.m. to finish playing it? He was so impressed by the game that the next day he wrote to inventor Charles Darrow and offered to buy it!






– that the first rickshaw was invented in 1869 by an American Baptist minister, the Rev. E. Jonathan Scobie, to transport his invalid wife around the streets of Yokohama?






– that to encourage use of his new invention, the shopping cart, market owner Sylvan Goldman hired fake shoppers to push the carts around his store in Oklahoma City? Seems his customers were reluctant to give up their hand-carried baskets.






– that the trademarked name “Baby Ruth” was inspired by President Grover Cleveland’s daughter, Ruth, and not by Babe Ruth?






– that J.B. Dunlop, one inventor of the pneumatic tire, was a veterinary surgeon?






– that Thomas Edison’s patent application on his phonograph was approved by the Patent Office in just seven weeks? In contrast, if took Gordon Gould, the inventor of the laser, 30 years to obtain his patent – finally awarded in 1988!






– that the first Apple computer was born in Steve Jobs’ parents’ garage? College students Jobs and his partner Steve Wozniak worked furiously in that garage assembling computers for fellow students and were totally unprepared for their first commercial order for 50 computers. To raise the needed $1300 for parts, Jobs sold his old VW bus and Wozniak sold his Hewlett Packard calculator. The next year – 1977 – Apple sales hit $800,000 and went on to become a Fortune 500 company in a record five years!






– that “patent leather” got its name because the process of applying the polished black finish to leather was once patent

Interesting Facts..> Geography

Guinea has the wettest capital on Earth, with 3.7 metres of rain a year.



Clipperton Island wins our prize for the most unusual looking country.


Only two countries in the world are doubly landlocked: Liechtenstein and Uzbekistan.


Sick of crowds? Move to Greenland! Greenlanders have 38 square kilometres of land per person.


If you thought Antarctica was inhospitable, think again - its land area is only ninety-eight percent ice. Reassuringly, the other 2% is categorised as "barren rock".


The Mall in Washington, D.C. is 1.4 times larger than Vatican City.


The four largest nations are Russia, China, USA, and Canada.


Brazil takes up 47.8% of South America.


Canada lays claim to more water than any other nation.


Almost the entire Cook Islands are covered by forest.


Contrary to the popular rhyme, the rain falls mainly on Guinea.


Australia has more than 28 times the land area of New Zealand, but its coastline is not even twice as long.

Ten of Those Minor Inventions

Who invented the wire coat hanger in 1903?



Albert J. Parkhouse. He was an employee of the Timberlake Wire and Novelty company in Jackson Michigan. After hearing many employees complain about insufficient coat hooks he bent a piece of wire into two ovals with each end of the wire twisted to form a hook.






Who invented the first workable adding machine in the 1800s?


William Seward Burroughs. The first machines his company sold in 1887 were almost impossible to use properly. They were recalled, corrections made and by 1895 the company he cofounded sold 284 machines. He passed away in 1898 at the age of 43.






What did the Swiss Jost Burgi invent in the 16th century that made the day for clock watchers?


The minute hand.. He invented it in 1577 for the astronomer Tycho Brahe who wanted an accurate clock for star gazing.






Who was credited with being the first person to wear a wrist watch?


Blaise Pascal. This young French genius (1623-1662) attached his pocket watch to his wrist with a piece of string. He is also credited with inventing an early calculator.






What product that typists often use did Bette Nesmith Graham invent?


White Out. In the 1950s she noticed that painters covered their mistakes with paint. This led her to think why not paint over typing errors. This mother of "The Monkees" Michael Nesmith went on to make a fortune with a company originally called Mistake Out. She died in 1980 just months after selling the company for 47 million dollars.






What is the name of the card filing system that rotates on a cylinder?


Rolodex. Arnold Neustadter started selling Rolodex in the 1950s. This Brooklyn born inventor died in 1996.






What multipurpose office and home product did Richard Drew invent in 1930?


Scotch tape. He also invented masking tape in 1925 while working for the 3M company. Another 3M employee John A. Borden invented the tape dispenser in 1932.






Who invented the telephone pager in 1949?


Al Gross. Also known as a beeper, it first saw use in New York City's Jewish hospital. This Canadian born (Toronto) US citizen also invented the walkie talkie.






In what country was the first ballpoint manufacturing factory opened?


Argentina. Hungarian brothers Ladislas and Georg Biro fled to Argentina when World War II broke out but by 1943 they had enough money to set up a factory. The pens were not very useful yet as they had to be held straight up and still left smudges on the paper.






In what country was the double oval standard (or GEM) paperclip designed?


England. The first patent for the "Gem" clip was issued to William Middlebrook in 1899. After over 100 years it is still proving to be the most popular type of paperclip!

Interesting Science Facts You Maybe Don't Know

Interesting Science Facts You Maybe Don't Know






It's time to refresh our brains with another list of fascinating factlets. These mini-facts are all science based and should be news to some readers.










1. Raindrops are not shaped like a teardrop (as they are almost always depicted in drawings) – they are actually spherical.




2. When something "sublimes" it turns directly into a gas from a solid – bypassing the liquid state. This is what would happen if you throw dry-ice into a fire.



3. Gorillas sleep in nests – they weave together soft foliage and bent branches from trees. Males tend to like sleeping on the ground while females like to have their nests in trees.

4. Champagne doesn't fizz because of carbon dioxide – it fizzes because of dirt or dust. In a completely smooth glass with no dust molecules in it, champagne would be completely still.

5. Most digestion occurs, not in the stomach, but in the small intestine. This may be the reason that a person can be bulimic whilst still staying fat.

6. The red juice that comes out of rare steak is not blood – it is myoglobin a close relative of blood. Almost all the blood has been removed from a steak by the time it hits the market.


7. Plastic bags are better than paper bags for the environment. The manufacturing process that makes paper bags requires far more energy than that which produces plastic. Recycling paper bags takes more energy than recycling plastic, and paper bags take up more space in a landfill. Because landfills are usually airtight beneath the surface, paper and plastic are equally bad at biodegrading.

8. Polar bears are fascinating creatures. Their fur is transparent (not white), their skin is black (not white), and when kept in warm humid environments, their fur can turn green from algae.

9. Pet allergies are usually not allergies to fur but allergies to the animal's dead skin, saliva, or waste matter. Regularly cleaning pets can dramatically reduce allergies.


10. The tongue map is a lie – you can taste all tastes on all parts of the tongue. The tongue map is derived from a discredited German paper from 1901.

11. When you hold a shell to your ear to hear the sea, the sound you hear is actually your own blood rushing through your veins! You can use any cup shaped object to hear this effect.



12. When you are alive, your brain is pink. When you die, it turns grey. While we describe the brain as "gray matter" and "white matter", this is not a true description of its color.

13. Mercury, the fascinating liquid metal is not the only liquid metal. Gallium is solid at room temperature but will melt if held in your hand, caesium (Cs), and francium (Fr) – the second rarest naturally occurring element, can also be liquid at or near room temperature.


14. Dolphins don't drink water – if they drank sea water it would make them ill and potentially kill them. They get all of their liquid needs through the foods they eat.





If you like this article Subscribe to MediaDump new content, follow us on Facebook and Twitter and check most popular posts from around the web:

Fun facts about engineering, science and technology

1. 220 million tons of old computers and other technological hardware are trashed in the United States each year.



2. A diamond will not dissolve in acid. The only thing that can destroy it is intense heat.


3. According to Moore's Law, microchips double in power every 18 to 24 months.


4. Albert Einstein won the Nobel Prize for physics in 1921.


5. Although the famous first flight at Kitty Hawk took place on December 17, 1903, the secretive Wright Brothers did not demonstrate the technology to the broader public until August 8, 1908.


6. As of early 2009, there have been 113 space shuttle flights since the program began in 1981.


7. Bill Clinton's inauguration in January 1997 was the first to be webcast.


8. Chuck Yeager blasted through the sound barrier at Edwards Air Force Base in 1947.


9. Einstein received the Nobel Prize for Physics in 1921 for his explanation of the photoelectric effect, the phenomenon by which electrons are knocked out of matter by electromagnetic radiation such as light.


10. In 1901, the Spanish engineer Leonar do Torres-Quevedo was responsible for the earliest developments in the remote control with his Telekine that was able to do "mechanical movements at a distance."

20 Interesting facts.

1. A zebra is white with black stripes.







2. All the planets in our solar system rotate anticlockwise, except Venus. It is the only planet that rotates clockwise.






3. Hummingbirds are the only animal that can also fly backwards.






4. Insects do not make noises with their voices. The noise of bees, mosquitoes and other buzzing insects is caused by rapidly moving their wings.






5. The cockroach is the fastest animal on 6 legs covering a meter a second.






6. The word "listen" contains the same letters as the word "silent".






7. The only 2 animals that can see behind itself without turning it's head are the rabbit and the parrot.






8. A 'jiffy' is an actual unit of time for 1/100th of a second.






9. India invented the Number System. Zero was invented by Aryabhatta.






10. The whip makes a cracking sound because its tip moves faster than the speed of sound.






11. A hippopotamus can run faster than a man.






12. India never invaded any country in her last 10000 years of history.






13. 'Hippopotomonstrosesquippedaliophobia' is the fear of long words.






14. Didaskaleinophobia is the fear of going to school.






15. A snail can sleep for 3 years.






16. The names of the continents all end with the same letter with which they start.






17. In 1883 the explosion of the volcano Krakatau put so much dust into the earth's atmosphere that sunsets appeared green and the moon appeared blue around the world for almost two years.






18. "Almost" is the longest word in the English language with all the letters in alphabetical order.






19. Twenty-Four-Karat Gold is not pure gold since there is a small amount of copper in it. Absolutely pure gold is so soft that it can be molded with the hands.






20. Electricity doesn't move through a wire but through a field around the wire.

10 Interesting scientific Facts

1 – The speed of light is generally rounded down to 186,000 miles per second. In exact terms it is 299,792,458 m/s (equal to 186,287.49 miles per second).







2 – It takes 8 minutes 17 seconds for light to travel from the Sun’s surface to the Earth.






3 – 10 percent of all human beings ever born are alive at this very moment.






4 – The Earth spins at 1,000 mph but it travels through space at an incredible 67,000 mph.






5 – Every year, over one million earthquakes shake the Earth.






6 – When Krakatoa erupted in 1883, its force was so great it could be heard 4,800 kilometers away in Australia.






7 – Every second around 100 lightning bolts strike the Earth.






8 – Every year lightning kills 1000 people.






9 – In October 1999 an Iceberg the size of London broke free from the Antarctic ice shelf .






10 – If you could drive your car straight up you would arrive in space in just over an hour.

Levi.s Jeans

No item of clothing is more American than the blue jeans invented in 1873 by Jacob Davis and Levi Strauss. These two visionary immigrants, turned denim, thread and a little metal into the most popular clothing product in the world. Waist overalls, was the traditional name for work pants, which is what these first jeans were called. The word jeans became more popular around 1960 when the baby-boom generation adopted the term for its favorite type of pants, blue jeans.. THE DID YOU KNOW?


Invention: blue jeans






Definition: noun / waist overalls, jeans, Levi's® jeans


Function: Clothes, especially pants, that are usually close-fitting and created from the rugged cotton twill textile that is colored blue with indigo dye


Patent: 139,121 (US) issued May 20, 1873 for Fastening Pocket-Openings


Inventor: Jacob Davis (aka Jacob Youphes)






Criteria: First to invent. First to patent. First practical.


Birth: 1834 in Riga Latvia


Death: 1908 in San Francisco, California


Nationality: German


Inventor: Levi Strauss (aka Loeb Strauss)






Criteria: First to patent. First practical. Entrepreneur.


Birth: February 26, 1829 in Buttenheim, Germany


Death: September 27, 1902 in San Francisco, California


Nationality: American (of German decent)


Milestones:


1847 Strauss family moves to New York City where Levi joined his brothers dry-goods business


1853 Levi moves to San Francisco, California to establishing a dry-goods business Levi Strauss&Co.


1854 Jacob moves to New York, then to San Francisco, California then to Canada for nine years


1868 Jacob settled in Reno, Neveda tailoring clothing and manufacturing tents and horse blankets


1871 Jacob who was using rivets on horse blankets, decides to try them on pant pockets for strength


1872 Jacob wrote a letter to Levi suggests that they hold the riveted pants patent rights together.


1872 on August 8, filed patent application for Improvements in Fastening Pocket-Openings


1873 patent 139,121 awarded to Jacob Davis and one half assigned to Levi Strauss & Co.


1873 Levi hires Jacob to oversee production of the riveted pants at the San Francisco plant


1875 Levi and two associates purchased the Mission and Pacific Woolen Mills


1890 the year that the lot number "501®" was first used to designate the denim waist overalls


1935 Levi's® jeans for women were first featured in Vogue magazine


1936 The red Tab Device was created to help identify Levi's® 501® jeans from a distance


1960 The word jeans became popular when the baby-boom generation used the term for the pants


jeans, blue jeans, levi's, denim waist overalls, 501, dungaree, Levi Strauss, Jacob Davis, invention, history, inventor of, history of, who invented, invention of, fascinating facts.


The Story:


The first jeans came in two styles, indigo blue and brown cotton "duck." Unlike denim, the duck material never became soft and comfortable so it was eventually dropped from the line. Although denim pants had been around as work wear for many years, historically dating back to England in the 1600s with a fabric there called denim, it was the first use of rivets that created what we now call jeans. "Waist overalls" was the traditional name for work pants, which is what these first jeans were called. The word jeans became more popular around 1960 when the baby-boom generation adopted the term for its favorite type of pants. How were blue jeans invented is a simple story.






Levi Strauss came to San Francisco in 1853, at the age of twenty-four, to open a west coast branch of his brothers' New York dry goods business. He had spent a number of years learning the trade in New York after emigrating there from his native Germany. He built his business into a very successful operation over the next twenty years, making a name for himself not only as a well-respected businessman, but as a local philanthropist as well.






One of Levi's many customers was a tailor named Jacob Davis. Originally from Latvia, Jacob lived in Reno, Nevada, and regularly purchased bolts of cloth from the wholesale house of Levi Strauss & Co. Among Jacob's customers was a difficult man who kept ripping the pockets of the pants that Jacob made for him. Jacob tried to think of a way to strengthen the man's trousers, and one day hit upon the idea of putting metal rivets at the points of strain, such as on the pocket corners and at the base of the button fly.






These riveted pants were an instant hit with Jacob's customers and he worried that someone might steal this great idea. He decided he should apply for a patent on the process, but didn't have the $68 that was required to file the papers. He needed a business partner and he immediately thought of Levi Strauss.






In 1872 Jacob wrote a letter to Levi to suggest that the two men hold the patent together. Levi, who was an astute businessman, saw the potential for this new product and agreed to Jacob's proposal. On May 20, 1873, the two men received patent no.139,121 from the U.S. Patent and Trademark Office. That day is now considered to be the official "birthday" of blue jeans.






With the patent secured, Levi hired Jacob Davis to oversee production of the riveted pants at the Levi Strauss & Co. San Francisco plant. Sometime during 1873, the first riveted clothing was made and sold. (the exact date was lost along with the company records in the 1906 San Francisco earthquake and fire). Jacob Davis was in charge of manufacturing when Levi Strauss & Co. opened its two San Francisco factories.


In 1875 Levi and two associates purchased the Mission and Pacific Woolen Mills from the estate of former silver millionaire William Ralston. Much of the mill's fabric was used to make the Levi Strauss & Co. "blanket-lined" pants and coats.






The denim for the riveted work pants came from the Amoskeag Mill in Manchester, New Hampshire, a company known for the quality of its fabrics. Within a very short time, all types of working men were buying the innovative new pants and spreading the word about their unrivaled durability. Hard to imagine that back in 1885, when denim first established itself as a reliable work wear cloth for a working man's garment — that a pair of Levi overalls cost $1.25. Brand new.






Holding a patent on this process meant that for nearly twenty years, Levi Strauss & Co. was the only company allowed to make riveted clothing until the patent went into the public domain.. Around 1890, these pants were assigned the number 501, which they still bear today. When the patent expired, dozens of garment manufacturers began to imitate the original riveted clothing made popular by Levi Strauss & Co.






In the 1950s, high school kids put them on as a radical way of defining themselves, of wanting to look and be more adult — and dangerous and rebellious against adults because adults didn't wear jeans. A decade later, blue jeans became a symbol of egalitarianism, a uniform for young adult baby boomers waging a generational war. In the 1970s Me Decade and the beginnings of celebrity culture surfaced, jeans were definitely about being sexy and all about fashion.






In 1980 came the controversial Calvin Klein ad slogan heard around the world. Who can ever forget 15-year-old Brooke Shields (barely old enough to get her driver's permit) purring into living rooms "Nothing comes between me and my Calvins"? As Vogue magazine editor in 1988, Anna Wintour's first cover was a pair of Guess? stonewash jeans teamed with a Christian Lacroix bejeweled top. The 1990s took denim onto country-western dance floors, onto the red carpet and created puzzling fashion styles from born-to-be-torn grunge jeans to baggy hip-hop jeans to rock star appeal — all adding to the confusion of casual Fridays.






The term "Levi's," though, was not the company's--it originated with the public, just as the public invented the term "coke" for Coca-Cola. But when the public started referring to the pants generically as "Levi's," the company quickly trademarked it. No item of clothing is more American than the blue jeans invented and perfected in the last quarter of the19th century by Jacob Davis and Levi Strauss These two visionary immigrants, turned denim, thread and a little metal into the most popular clothing product in the world - blue jeans.