Limba Engleza
Thomas Alva Edison
Introduction
Thomas
Alva Edison (February 11, 1847 - October 18, 1931) was an American inventor and
businessman who developed many devices which greatly influenced life around the
world. Dubbed 'The Wizard of Menlo Park' by a newspaper reporter, he
was one of the first inventors to apply the principles of mass production to
the process of invention, and therefore is often credited with the creation of
the first industrial research laboratory.
Some
of his inventions were not completely original but amounted to improvements of
earlier inventions. Also, many of the inventions attributed to him were
actually created by one or more of the numerous employees working under his
direction. Nevertheless, Edison is considered one of the most prolific
inventors in history, holding 1,097 U.S.
patents in his name, as well as many patents in the United
Kingdom, France
and Germany.
Structured
in three chapters, the paper starts by describing Thomas Edison's life bla bla .
The second chapter presents all his important inventions and the third chapter makes a walk through
his failed inventions.
The reason why I have chosen this
subject is because Thomas Edison was more responsible than any one else for
creating the modern world . No one
did more too shape the physical/cultural makeup of present day
civilization. Accordingly, he was the most influential figure of the
millennium.'
The Life of Thomas Edison
Thomas
Alva Edison was born on February 11, 1847 in Milan, Ohio; the seventh
and last child of Samuel and Nancy Edison. When Edison was seven his family
moved to Port Huron, Michigan. Edison
lived here until he struck out on his own at the age of sixteen. Edison had very little formal education as a child,
attending school only for a few months. He was taught reading, writing, and
arithmetic by his mother, but was always a very curious child and taught
himself much by reading on his own. This belief in self-improvement remained
throughout his life.
Edison began working at an early age, as most boys did at
the time. At thirteen he took a job as a newsboy, selling newspapers and candy
on the local railroad that ran through Port Huron
to Detroit. He
seems to have spent much of his free time reading scientific, and technical
books, and also had the opportunity at this time to learn how to operate a
telegraph. By the time he was sixteen, Edison
was proficient enough to work as a telegrapher full time.
The
development of the telegraph was the first step in the communication
revolution, and the telegraph industry expanded rapidly in the second half of
the 19th century. This rapid growth gave Edison
and others like him a chance to travel, see the country, and gain experience.
Edison worked in a number of cities throughout the United
States before arriving in Boston in 1868. Here Edison
began to change his profession from telegrapher to inventor. He received his
first patent on an electric vote recorder, a device intended for use by elected
bodies such as Congress to speed the voting process. This invention was a
commercial failure. Edison resolved that in
the future he would only invent things that he was certain the public would
want.
Edison
moved to New York City
in 1869. He continued to work on inventions related to the telegraph, and
developed his first successful invention, an improved stock ticker called the
'Universal Stock Printer'. For this and some related inventions Edison was paid $40,000. This gave Edison the money he
needed to set up his first small laboratory and manufacturing facility in Newark, New
Jersey in 1871. During the next five years, Edison
worked in Newark
inventing and manufacturing devices that greatly improved the speed and
efficiency of the telegraph. He also found to time to get married to Mary
Stilwell and start a family.
In
1876 Edison sold all his Newark manufacturing
concerns and moved his family and staff of assistants to the small village of Menlo Park,
twenty-five miles southwest of New
York City. Edison
established a new facility containing all the equipment necessary to work on
any invention. This research and development laboratory was the first of its
kind anywhere; the model for later, modern facilities such as Bell
Laboratories, this is sometimes considered to be Edison's
greatest invention. Here Edison began to
change the world.
The
first great invention developed by Edison in Menlo Park was the tin foil phonograph. The
first machine that could record and reproduce sound created a sensation and brought Edison international fame. Edison
toured the country with the tin foil phonograph, and was invited to the White
House to demonstrate it to President Rutherford B. Hayes in April 1878.
Edison next undertook his greatest challenge, the
development of a practical incandescent, electric light. The idea of electric
lighting was not new, and a number of people had worked on, and even developed
forms of electric lighting. But up to that time, nothing had been developed
that was remotely practical for home use. Edison's
eventual achievement was inventing not just an incandescent electric light, but
also an electric lighting system that contained all the elements necessary to
make the incandescent light practical, safe, and economical. After one and a
half years of work, success was achieved when an incandescent lamp with a
filament of carbonized sewing thread burned for thirteen and a half hours. The
first public demonstration of the Edison's incandescent lighting system was in
December 1879, when the Menlo Park
laboratory complex was electrically lighted. Edison
spent the next several years creating the electric industry. In September 1882,
the first commercial power station, located on Pearl Street in lower Manhattan, went into operation providing
light and power to customers in a one square mile area; the electric age had
begun.
Edison next undertook his greatest challenge, the
development of a practical incandescent, electric light. The idea of electric
lighting was not new, and a number of people had worked on, and even developed
forms of electric lighting. But up to that time, nothing had been developed
that was remotely practical for home use. Edison's
eventual achievement was inventing not just an incandescent electric light, but
also an electric lighting system that contained all the elements necessary to
make the incandescent light practical, safe, and economical. After one and a
half years of work, success was achieved when an incandescent lamp with a
filament of carbonized sewing thread burned for thirteen and a half hours. The
first public demonstration of the Edison's incandescent lighting system was in
December 1879, when the Menlo Park
laboratory complex was electrically lighted. Edison
spent the next several years creating the electric industry. In September 1882,
the first commercial power station, located on Pearl Street in lower Manhattan, went into operation providing
light and power to customers in a one square mile area; the electric age had
begun.
The success of his electric light
brought Edison to new heights of fame and
wealth, as electricity spread around the world. Edison's
various electric companies continued to grow until in 1889 they were brought
together to form Edison General Electric. Despite the use of Edison in the
company title however, Edison never controlled
this company. The tremendous amount of capital needed to develop the
incandescent lighting industry had necessitated the involvement of investment
bankers such as J.P. Morgan. When Edison General Electric merged with its
leading competitor Thompson-Houston in 1892, Edison
was dropped from the name, and the company became simply General Electric.
This
period of success was marred by the death of Edison's
wife Mary in 1884. Edison's involvement in the business end of the electric industry
had caused Edison to spend less time in Menlo
Park. After Mary's death, Edison was there even less,
living instead in New York City
with his three children. A year later, while vacationing at a friends house in
New England, Edison met Mina Miller and fell
in love. The couple was married in February 1886 and moved to West
Orange, New Jersey where Edison had purchased an estate, Glenmont, for his bride.
Thomas Edison lived here with Mina until his death.
When
Edison moved to West Orange, he was doing experimental work in makeshift
facilities in his electric lamp factory in nearby Harrison, New Jersey.
A few months after his marriage, however, Edison decided to build a new
laboratory in West Orange itself, less than a
mile from his home. Edison possessed the both the resources and experience by
this time to build, 'the best equipped and largest laboratory extant and
the facilities superior to any other for rapid and cheap development of an
invention '. The new laboratory complex consisting of five buildings
opened in November 1887. A three story main laboratory building contained a
power plant, machine shops, stock rooms, experimental rooms and a large
library. Four smaller one story buildings built perpendicular to the main
building contained a physics lab, chemistry lab, metallurgy lab, pattern shop,
and chemical storage. The large size of the laboratory not only allowed Edison to work on any sort of project, but also allowed
him to work on as many as ten or twenty projects at once. Facilities were added
to the laboratory or modified to meet Edison's
changing needs as he continued to work in this complex until his death in 1931.
Over the years, factories to manufacture Edison
inventions were built around the laboratory. The entire laboratory and factory
complex eventually covered more than twenty acres and employed 10,000 people at
its peak during World War One (1914-1918).
After
opening the new laboratory, Edison began to
work on the phonograph again, having set the project aside to develop the electric
light in the late 1870s. By the 1890s, Edison
began to manufacture phonographs for both home, and business use. Like the
electric light, Edison developed everything
needed to have a phonograph work, including records to play, equipment to
record the records, and equipment to manufacture the records and the machines.
In the process of making the phonograph practical, Edison
created the recording industry. The development and improvement of the
phonograph was an ongoing project, continuing almost until Edison's
death.
The Inventions of Thomas Edison
Phonograph
- History
The
first great invention developed by Edison in Menlo Park was the tin foil phonograph. While
working to improve the efficiency of a telegraph transmitter, he noted that the
tape of the machine gave off a noise resembling spoken words when played at a
high speed. This caused him to wonder if he could record a telephone message.
He began experimenting with the diaphragm of a telephone receiver by attaching
a needle to it. He reasoned that the needle could prick paper tape to record a
message. His experiments led him to try a stylus on a tinfoil cylinder, which,
to his great surprise, played back the short message he recorded, 'Mary
had a little lamb.'
The
word phonograph was the trade name for Edison's
device, which played cylinders rather than discs. The machine had two needles:
one for recording and one for playback. When you spoke into the mouthpiece, the
sound vibrations of your voice would be indented onto the cylinder by the
recording needle. This cylinder phonograph was the first machine that could
record and reproduce sound created a sensation and brought Edison
international fame.
August
12, 1877, is the date popularly given for Edison's
completion of the model for the first phonograph. It is more likely, however,
that work on the model was not finished until November or December of that
year, since he did not file for the patent until December 24, 1877. He toured
the country with the tin foil phonograph, and was invited to the White House to
demonstrate it to President Rutherford B. Hayes in April 1878.
In
1878, Thomas Edison established the Edison Speaking Phonograph Company to sell
the new machine. He suggested other uses for the phonograph, such as: letter
writing and dictation, phonographic books for blind people, a family record
(recording family members in their own voices), music boxes and toys, clocks
that announce the time, and a connection with the telephone so communications
could be recorded.
Disc
Phonograph - History
Cylinders
peaked in popularity around 1905. After this, discs and disc players, most
notably the Victrolas, began to dominate the market. Columbia Records, and Edison competitor, had stopped marketing cylinders in
1912. The Edison Company had been fully devoted to cylinder phonographs, but,
concerned with discs' rising popularity, Edison
associates began developing their own disc player and discs in secret. Dr.
Jonas Aylsworth, chief chemist for Edison, and
later after his retirement in 1903, a consultant for the company, took charge
of developing a plastic material for the discs. The aim was to produce a
superior-sounding disc that would outperform the rivals' shellac records, which
were prone to wear and warping. Another difference from competitors' discs was
that the vertical-cut method was to be used for the grooves. In this manner,
the stylus would bob up and down in the groove, rather than from side to side
or laterally. Ten-inch records would run for 5 minutes per side at
approximately 80 r.p.m.
Although
Edison associates initially worked on the project in secret, when Edison discovered it, he took control of this new project
and gave it much of his personal attention.
Aylsworth
molded phenol and formaldehyde mixed with wood-flour and a solvent into a
heat-resistant disc. This material always remained absolutely plane, which was
essential as it formed the core of the disc record. A phenolic resin varnish
called Condensite was applied to the core, and then the disc was stamped in the
record press. The finished 10' disc weighed ten ounces, heavier than most,
partially due to the 1/4' thickness of the record. A diamond point was
obtained for the stylus. The Disc Phonograph and the Edison Discs were designed
to be an entire system, incompatible with other discs or disc players.
The
new Edison Disc Phonograph was shown for the first time publicly at the Fifth
Annual Convention for the National Association of Talking Machine Jobbers at Milwaukee, Wisconsin,
on July 10-13th, 1911. Press reported that the new machine was based on Edison's British 1878 patent in order to deter claims of
copyright infringement with Victor or Berliner. The new machine was also
mentioned in the Edison Phonograph Monthly in July of 1911, but it was over a
year before disc players or discs would be offered for sale.
By
the end of 1912, three basic models of the Edison Disc Phonograph had been
designed, ranging in price from $150 to $250, and the company salesmen took
them around the country. Soon after, the choice of models was extended to
feature less expensive players and luxury machines in stylish wood cabinets.
Prices for the discs started from $1.15 to $4.25, but later came down to $1.35
to $2.25. The discs were expensive to make because of the complicated chemical
processes used for them.
Initial
public reaction was not encouraging for several reasons. The Edison cabinets
were deemed to be less attractive than the Victrolas, and customers were
required to buy Edison discs only for Edison
players, since they were not compatible with other players. The laminated
surface of the discs also had a tendency to detach from the core material, and
surface noise was frequently apparent, which contradicted the aim of perfection
that the company was trying to achieve with its recordings. Still, the
phonographs and discs were touted as being acoustically better than those of
the competitors. In order to bolster claims of superiority, Edison
claimed that his records could be played 1,000 times without wear
Recitals
were also conducted to prove the merit of the discs. Edison
recording artists would sing along with a disc recording of their voices,
daring the audience to be able to tell the difference. In late 1915, Edison began its famous Tone Tests, which featured
artists alternating their live performance on a darkened stage with that on the
disc in front of large audiences, challenging them to detect a difference.
Reaction was positive to these tests, and reinforced the Edison
motto that the discs were 're-creations' of performances, not merely
recordings of them.
Additional
advertising for the Diamond Disc was secured through promotion of the Edison film The Voice of the Violin, made in 1915, which
featured a Tone Test by Anna Case. (The Library of Congress copy is incomplete
and, unfortunately, is lacking Case's performance.)
On
the disc label, sides were indicated by 'L' and 'R',
referring to the left side or the right side when stored vertically. The early
disc issues contained the Edison trademark, Edison's image, the title of the
selection, and the composer, all pressed into the glossy black surface of the
disc using a half-tone electrotype. The early issues did not carry the artists'
names, reflecting Edison's policy of not
seeking out name acts, but supposedly relying on the quality of the music
alone. In 1915, the artists' names began to be added to the labels. In 1921,
black paper labels with white Roman type began to be used, and were changed at
the end of 1923 to white labels.
By
1916, demand increased for console cabinets to house the disc players. The
Edison Company produced a series of period models to compete with those of the
Victor Company. The designer for the cabinets was H.D. Newson from the W.A.
French Furniture Company of Minneapolis.
Named 'The Art Models,' these cabinets came in English, French, and
Italian period styles, as well as Gothic styles. Prices ranged from $1,000 to
$6,000. Advertising for these models made it clear that the players themselves
were the same as lower-priced models; the inflated cost was for the cabinet.
In
1917 when the U.S.
became involved in World War I, the Edison Company created the Army and Navy
Model in answer to a request for machines from the United States Army
Depot
Quartermaster in New York.
The simple, basic machine sold for $60. The Department of War never purchased
any, but individual units bought them, some taking them overseas. The Army and
Navy Model was discontinued after the war's end.
By
1917, the Disc Phonograph had garnered considerable success in the marketplace.
This good fortune continued for almost seven years. In contrast, the cylinder
phonograph business declined; by 1925, the remaining cylinder customers had to
order directly from the factory. By 1920, Edison
was the only disc company not using steel needles or the lateral method of
grooves.
By
1924, business began to sour with the advent of competition from radio.
Operations were cut back, and experimentation began with long-playing records.
These were introduced in October 1926 along with four new console disc
phonographs. As a concession to the marketplace, attachments were also offered
so that the Edison phonographs could play the
laterally-cut records of competitors.
By
the latter half of the 20's, the company started to diversify its interests in
an attempt to stay viable. Thoughts of moving pictures with sound led the
company to develop an Ediscope which featured still pictures with narration.
This was envisioned as being appropriate for the children's market, since it
could be used for fairy tales and educational nature talks. Work was also begun
on the Cine-Music Phonograph, which was conceived to supply musical
accompaniment to motion pictures.
Edison
entered into the radio business in 1928 by taking over the Aplitdorf-Bethlehem
Electrical Company of Newark,
a move which allowed him to produce radio-phonographs. The Edison Company
further expanded into the field of radio by making programs for radio on
long-playing discs. Radio station WAAM of Newark, NJ, agreed to use the new
Rayediphonic Reproducing Machine and Radiosonic records in 1929, with the first
Radiosonic broadcast being aired on April 4. It appeared that the company had
finally found a profitable outlet.
In
the summer of 1929, the Edison company gave
into the popular trend and introduced the Edison Portable Disc Phonograph with
New Edison Needle Records, offering both the Diamond Discs and the new needle
records simultaneously.
These
changes did not measurably improve business, and on October 21, orders were
given to close the Edison disc business, with
the company stating that it would focus on the manufacture of its
radio-phonographs in the future.
Kinetophones - History
From
the inception of motion pictures, various inventors attempted to unite sight
and sound through 'talking' motion pictures. The Edison Company is
known to have experimented with this as early as the fall of 1894 under the
supervision of W. K. L. Dickson with a film known today as Dickson Experimental
Sound Film. The film shows a man, who may possibly be Dickson, playing violin
before a phonograph horn as two men dance.
By
the spring of 1895, Edison was offering
Kinetophones--Kinetoscopes with phonographs inside their cabinets. The viewer
would look into the peep-holes of the Kinetoscope to watch the motion picture
while listening to the accompanying phonograph through two rubber ear tubes
connected to the machine (the kinetophone). The picture and sound were made
somewhat synchronous by connecting the two with a belt. Although the initial
novelty of the machine drew attention, the decline of the Kinetoscope business
and Dickson's departure from Edison ended any
further work on the Kinetophone for 18 years.
In
1913, a different version of the Kinetophone was introduced to the public. This
time, the sound was made to synchronize with a motion picture projected onto a
screen. A celluloid cylinder record measuring 5 1/2' in diameter was used
for the phonograph. Synchronization was achieved by connecting the projector at
one end of the theater and the phonograph at the other end with a long pulley.
Nineteen
talking pictures were produced in 1913 by Edison,
but by 1915 he had abandoned sound motion pictures. There were several reasons
for this. First, union rules stipulated that local union projectionists had to
operate the Kinetophones, even though they hadn't been trained properly in its
use. This led to many instances where synchronization was not achieved, causing
audience dissatisfaction. The method of synchronization used was still less
than perfect, and breaks in the film would cause the motion picture to get out
of step with the phonograph record. The dissolution of the Motion Picture
Patents Corp. in 1915 may also have contributed to Edison's
departure from sound films, since this act deprived him of patent protection
for his motion picture inventions.
Electricity and Lightbulb -
History
Thomas Edison's greatest challenge
was the development of a practical incandescent, electric light. Contrary to
popular belief, he didn't 'invent' the lightbulb, but rather he
improved upon a 50-year-old idea. In 1879, using lower current electricity, a
small carbonized filament, and an improved vacuum inside the globe, he was able
to produce a reliable, long-lasting source of light. The idea of electric
lighting was not new, and a number of people had worked on, and even developed
forms of electric lighting. But up to that time, nothing had been developed
that was remotely practical for home use. Edison's
eventual achievement was inventing not just an incandescent electric light, but
also an electric lighting system that contained all the elements necessary to
make the incandescent light practical, safe, and economical. After one and a
half years of work, success was achieved when an incandescent lamp with a
filament of carbonized sewing thread burned for thirteen and a half hours.
There
are a couple of other interesting things about the invention of the light bulb:
While most of the attention was on the discovery of the right kind of filament
that would work, Edison actually had to invent a total of seven system elements
that were critical to the practical application of electric lights as an
alternative to the gas lights that were prevalent in that day.
These
were the development of:
- the parallel circuit,
- a durable light bulb,
- an improved dynamo,
- the underground conductor network,
- the devices for maintaining constant voltage,
- safety fuses and insulating materials, and
- light sockets with on-off switches.
Before
Edison could make his millions, every one of
these elements had to be invented and then, through careful trial and error,
developed into practical, reproducible components. The first public demonstration
of the Thomas Edison's incandescent lighting system was in December 1879, when
the Menlo Park
laboratory complex was electrically lighted. Edison
spent the next several years creating the electric industry.
The
modern electric utility industry began in the 1880s. It evolved from gas and
electric carbon-arc commercial and street lighting systems. On September 4,
1882, the first commercial power station, located on Pearl Street in lower Manhattan, went into operation providing
light and electricity power to customers in a one square mile area; the
electric age had begun. Thomas Edison's Pearl Street electricity generating
station introduced four key elements of a modern electric utility system. It
featured reliable central generation, efficient distribution, a successful end
use (in 1882, the light bulb), and a competitive price. A model of efficiency
for its time, Pearl Street
used one-third the fuel of its predecessors, burning about 10 pounds of coal
per kilowatt hour, a 'heat rate' equivalent of about 138,000 Btu per
kilowatt hour. Initially the Pearl
Street utility served 59 customers for about 24
cents per kilowatt hour. In the late 1880s, power demand for electric motors
brought the industry from mainly nighttime lighting to 24-hour service and
dramatically raised electricity demand for transportation and industry needs.
By the end of the 1880s, small central stations dotted many U.S. cities;
each was limited to a few blocks area because of transmission inefficiencies of
direct current (dc).
The
success of his electric light brought Thomas Edison to new heights of fame and
wealth, as electricity spread around the world. His various electric companies
continued to grow until in 1889 they were brought together to form Edison
General Electric. Despite the use of Edison in
the company title however, he never controlled this company. The tremendous
amount of capital needed to develop the incandescent lighting industry had
necessitated the involvement of investment bankers such as J.P. Morgan. When
Edison General Electric merged with its leading competitor Thompson-Houston in
1892, Edison was dropped from the name, and
the company became simply General Electric.
Edison Motion Pictures - History
Thomas
Edison's interest in motion pictures began before 1888, however, the visit of
Eadweard Muybridge to his laboratory in West Orange
in February of that year certainly stimulated his resolve to invent a camera
for motion pictures. Muybridge proposed that they collaborate and combine the
Zoopraxiscope with the Edison phonograph.
Although apparently intrigued, Edison decided
not to participate in such a partnership, perhaps realizing that the
Zoopraxiscope was not a very practical or efficient way of recording motion. In
an attempt to protect his future, he filed a caveat with the Patents Office on
October 17, 1888, describing his ideas for a device which would 'do for
the eye what the phonograph does for the ear' -- record and reproduce
objects in motion. He called it a 'Kinetoscope,' using the Greek
words 'kineto' meaning 'movement' and 'scopos'
meaning 'to watch.'
One
of Edison's first motion picture and the first
motion picture ever copyrighted showed his employee Fred Ott pretending to
sneeze. One problem was that a good film for motion pictures was not available.
In 1893, Eastman Kodak began supplying motion picture film stock, making it
possible for Edison to step up the production
of new motion pictures. He built a motion picture production studio in New Jersey. The studio
had a roof that could be opened to let in daylight, and the entire building was
constructed so that it could be moved to stay in line with the sun.
C.
Francis Jenkins and Thomas Armat invented a film projector called the Vitascope
and asked Edison to supply the films and manufacture the projector under his
name. Eventually, the Edison Company developed its own projector, known as the
Projectoscope, and stopped marketing the Vitascope. The first motion pictures
shown in a 'movie theater' in America
were presented to audiences on April 23, 1896, in New York City.
The Failed Inventions
Thomas Alva Edison held 1,093 patents for
different inventions. Many of them, like the lightbulb, the phonograph, and the
motion picture camera, were brilliant creations that have a huge influence on
our everyday life. However, not everything he created was a success; he also
had a few failures.
One
concept that never took off was Edison's
interest in using cement to build things. He formed the Edison Portland Cement
Co. in 1899, and made everything from cabinets (for phonographs) to pianos and
houses. Unfortunately, at the time, concrete was too expensive and the idea was
never accepted. Cement wasn't a total failure, though. His company was hired to
build Yankee Stadium in the Bronx.
From the beginning of the creation of motion
pictures, many people tried to combine film and sound to make
'talking' motion pictures. Here you can see to the left an example of
an early film attempting to combine sound with pictures made by Edison's assistant, W.K.L. Dickson. By 1895, Edison had created the Kinetophone--a Kinetoscope
(peep-hole motion picture viewer) with a phonograph that played inside the
cabinet. Sound could be heard through two ear tubes while the viewer watched
the images. This creation never really took off, and by 1915 Edison
abandoned the idea of sound motion pictures.
The
greatest failure of Thomas Edison's career was his inability to create a
practical way to mine iron ore. He worked on mining methods through the late
1880s and early 1890s to supply the Pennsylvania
steel mills' demand for iron ore. In order to finance this work, he sold all
his stock in General Electric, but was never able to create a separator that
could extract iron from unusable, low-grade ores. Eventually, Edison gave up on
the idea, but by then he had lost all the money he'd invested.
Conclusion
Thomas Alva Edison
was a man who influenced America
more than anyone else. He became throw his inventions one of the most important
figures that world knew. His name is immortal threw ages just because his
brilliant mind .
He was lucky
because he was a businessman too, and he could start the production of all his
invention which help us nowadays. Beside all this he ruined the hopes of others
peoples to try to assume the same inventions , as we can say now he registered
these devices with the original brand no copyright allowed.
In
my opinion, Thomas Edison was a person who deserves our respect for his
influence on political thought and for the long-lasting effects of all that he
accomplished during his long and fruitful career.
Bibliography
Books
(information)
1. Edison:
The man who made the future by
Ronald W. Clark
2. Edison:
Inventing the Century by Neil Baldwin
3. Edison
by Matthew Josephson. McGraw Hill