carbon arc lamp was the first widely-used type of electric light
and the first commercially successful form of electric lamp.
the rest of the types of lighting described in our Electric
Lighting pages, the arc light's development had to coincide
with basic power generation developments. As batteries, generators
and power conditioning technology developed arc lamps could be
made more sophisticated. The carbon rod was often replaced by
magnetite (iron ore) for longer life by 1905. The carbon arc lamp
led to other arc discharge lamps like the mercury
vapor, sodium and fluorescent
lamps. Today the lamp has been replaced by the xenon
Two arc lamps: single and double arc lamp designed by Elihu Thomson
and E.W. Rice for the Thomson-Houston Electric Company 1880s
Arc Lamp: Advantages:
-Super bright light, capable of lighting a large
length of street or a large factory interior
-Was the ONLY electric light available to light large areas from
1800 - 1901
-Was cheaper to light streets with the arc lamp than gas or oil
-Carbon rods had to be replaced after a short period
of time, this became a full time job in a city
-Produces dangerous UV-A, UV-B, and UV-C rays
-Created a buzzing sound and flickering as the light burned
-Created large amounts of RFI (radio frequency interference)
-Dangerous: it was a fire hazard, many theaters burned as a result of
the excessive heat or sparks emitted, also the unenclosed lamp could
easily electrocute or severally burn technicians.
-Carbon Monoxide emissions (bad for indoor use!) It only worked in the
past because buildings were poorly insulated and fresh air could enter.
Some of today's energy efficient buildings are almost air tight.
per watt: 2 - 7 (best rating is for an enclosed lamp)
*Lamp life (life of carbon rods): 75 hrs average (1890s)
175 hrs (1911)
600 hrs (magnetite electrode)
Life depends on the length of the electrode (hrs per inch was
*Color Temperature: NA
Warm up time: instant on
uses: outdoor lighting: street lighting, trolley route lighting,
film and slide projector lamps, indoor factory and mill lighting,
retail shop lighting and palace/ballroom lighting, search lights,
4 Minute Video on the Carbon Arc Lamp. Youtube must be accessible
on your internet server for this to work.
1.) How it Works:
is a spark or electric arc through the air between two carbon rods.
The rods must have a gap in between of the right size. If the gap is
too big than the arc will flicker more or may go out, if the gap is
to narrow than it will produce less light.
The first carbon was made of charcoal (made from wood). The carbon substance
is vaporized in the high temperature of the arc (around 6500
F, 3600 C). The carbon vapor is highly luminous (very bright) and this
is why we use carbon in the lamp. This light is much more useful and
bright than that of an arc between steel like in the Jacobs Ladder example
photo below. The carbon vapor and normal air ionizes easily which helps
make light. When the atoms of the carbon and air ionize it means they
give up and take on electrons. This happens as electric current passes
from one electrode (in this case one of the carbon rods) to the other
electrode. Lighting ionizes the air that is passes through.
A Jacobs Ladder, a common science teaching toy shows the electric arc
through air. The arc is not very bright compared to a carbon arc lamp.
The study of the behavior of the electric arc through gas is covered
in the field of plasma
Mercury, Containment and Buckyballs
The carbon arc lamp once lit produces a useful bright light, however
undesirable aspects exist. The lamp produces hot sparks and buckyballs
which can and have caused fires. Early arc lamps used in department
stores were a concern because hot sparks would randomly fall to the
floor, on people, or on merchandise. The lamp also produces UV-A, UV-B,
and UV-C light which are harmful to both the eyes and skin. Early arc
lamp makers didn't know about UV light yet, but did realize that diffusing
the light made for better quality light.
lamp inventors created glass globes to fit around the lamp. Some
globes were made of opal glass to diffuse the light and the silica glass
blocked some of the harmful UV rays. Early globes often had an open
top to allow heat to escape (see the various designs near the bottom
of this page here). These
protective globes are not to be confused with the "enclosed carbon
enclosed carbon arc was an arc lamp which completely enclosed
the electrodes. The upper electrode was fed through a hole in the top.
This enclosed lamp prevented oxygen from easily reaching the arc. With
less available oxygen the arc burned slower and the lamp life was greatly
Mercury Arc: Some early visionaries discovered that by adding
mercury into the enclosed arc lamp a green light was created. This was
an early predecessor to the mercury vapor lamp. When the hot lamp struck
it vaporized the mercury stuck to the inside of the bulb, this helped
produce better light with a higher efficiency. The mercury arc was not
popular and did not take over the market because it had an ugly greenish
color. It did get used as a germicidal lamp due to its increased UV
emission. We do not call this a "mercury vapor lamp", the
"mercury vapor lamp" as we know today uses a sealed low or
high pressure bulb/tube and the two electrodes are made of metal or
tungsten, not carbon sticks. We have a separate page for this more advanced
type of lamp here.
are made of Carbon-20 through 60. Buckyballs are giant molecules which
border on being a 'solid' not a small particle. These large molecules
behave strangely compared to normal molecules. There are up to 240 electrons
total, they act collectively when excited and oscillate back and forth
forming a surface plasmon. They are created in natural soot and charcoal
which is part of the process of making the carbon rods for the lamp.
One issue with the carbon arc lamp is that the rods of carbon
are burned away over time. Therefore if you have two carbon rods
firmly mounted the gap will grow bigger between as the carbon
rod itself is vaporized. Eventually the arc will cease when the
gap gets large enough. The solution to this problem in the first
experimental lamps was to use insulated pliers and slide the rods
close again as it burned.
make a commercial product (which is a central issue in all
of our lighting pages) inventors and engineers have to design
a system that is RELIABLE. While scientists can do experiments
and observations with handmade prototypes, it is up to the engineer
to labor over ways to make a lamp useful (in other words reliable
and easy to use/maintain) to the masses . This is difference
between scientists and engineers.
the carbon arc lamp inventors had to figure out a mechanical
way to feed carbons into the device as it burned up. Control
Engineering was used to figure out a way to sense the current
and voltage draw of the lamp (which changes as the gap gets bigger)
and control a set of magnets and devices that would keep the gap
size constant and lamp working for hours.
in the 1870s and before used clockwork type feeding devices -
gears, clutches and works by slowly feeding the carbons. Engineers
at the Thomson-Houston Company figured out how to use a differential
system which worked better than the early Brush clutch systems.
Feeding devices for arc lamps are a large subject.
Above Left: A lit arc lamp from
the 1880s as was used in urban lighting and factories. Photo by
the schematic above you will see how electricity is channeled
through devices which sense and react to current in order to do
1.) Keep the gap at the ideal distance
2.) Act as a resistor (ballast) to limit current to the arc
3.) Control and condition incoming power which may by unstable
of the early arc light system:
A Current Regular
developed by E.W. Rice Jr. allowed more lights to be places on
dynamo for sale in the 1880s, used in Philadelphia
In the quest to make better arc lamps which lasted longer and therefore
required less trimming (the term for adding new carbon rods) engineers
experimented with adding compounds to the carbon rods. William Wallace
who happened to be from the copper towns of Connecticut developed a
copper plated electrode with carbon in the center.
Flame Arc Lamp:
Until the 1890s most of the light emitted by the lamp came from the
glowing carbon tips. The flame arc lamp produced more carbon vapor which
made a flame that produced most of the light. The flame arc lamp lasted
much longer, now a lamp could last for days without trimming.
1904 Steinmetz used magnetite carbons to make much longer life. The
carbon rod was mostly made of magnetic oxides of iron. Sometimes titanium
carbide and titanium oxide were added as well. This lamp was a flame
arc lamp type.
The first work with
arc lamps was in the laboratory until the 1870s. Most of the
work on arc lamps occurred in Europe during the pre-1870s period.
The main reason why arc lamps were not on the streets until
that time is because a reliable dynamo was needed to produce
DC power. Prior to 1870 most people used batteries to power
the arc lamp. It was a difficult sell to clients because the
batteries were not reliable, very expensive, and had a short
life. Gramme's dynamo set off a race in 1869. In only a few
years many inventors had unique dynamo designs of their own,
and it took a short time to adapt the dynamo to work with arc
light systems. Finally the arc light was ready for commercial
the Yablochkov (Jablochkoff) candle was the first product,
it had two carbon rods side by side (see illustration) separated
by a plaster, it burned down from the top with the arc begin
kept at the idea gap width. This was a way to get around the
problem of feeding two carbon rods together in the regular lamp
model. It was a simple operation to replace the rods when finished.
The device produced an unsteady light that would range from
dark purple to bright white. Sometimes it went out, which would
lead to the entire series of lamps (up to six) going out. But
it was a important step and the first commercially successful
installations were small ( 1-12 lights). The first installation was
the lighting of the Mill of Heilmann, Ducommun, and Steinlein
at Mulhausen, France (1875). Another installation was the lighting of
La Chapelle railway station (France). Paris holds the record for the
first street lighting in 1875. The Thames Embankment (London) was lit
in 1878 (Using Jablochoff Candles). Despite these installations a lot
of work needed to be done. Understanding of electric power was crude,
and there was no way to measure power, or adequately control power systems
to get more performance.
Installations in North America:
F. Brush developed the first commercially successful arc light
systems in North America in Cleveland, OH (at Public Square 4/29/1879).
His design of arc light AND dynamo (a dynamo generates DC power) was
proven to be the best of several experimental systems by different inventors
at an exposition at the Franklin Institute in Philadelphia in 1977.
This event also inspired E.W. Rice Jr., Edwin
J. Houston, and Elihu Thomson to create arc
light systems of their own. When Thomas Edison traveled through Ohio,
he was inspired by Brush's arc light work and he initiated his own electric
light work. Brush improved not only the ability to add more lights to
the circuit, but developed the Brush Dynamo. This dynamo was a monumental
achievement in power generation.
Electric Light's first commercial success, and happier whales.
In 1880 authorities
in Wabash, Indiana discover that the Brush electric arc light system
for it's streets would cost $800 less per year than gas lighting. Also
they stated that they would get greater volume of illumination. This
was the beginning of the revolution across the world to switch to the
electric light. By proving to be economically better than oil and gas
the future was set. This also stopped the complete eradication of certain
whale species that provided the oil, these whales were already close
to extinction in the 1880's due to over-hunting.
in lights was made from coal. The coal was shipped to cities, and
cooked in a crucible, a gas resulted that supplied the town's light
systems. This process was very dirty, it produced massive amounts of
carbon monoxide and a coke remains that was then shipped out for other
uses as dirty combustible fuel. The electric arc light eliminated the
need for plants that produced urban localized pollution.
founded the Thomson-Houston Electric Company
which later absorbed the Brush Electric Company. E. W. Rice Jr.
helped develop a voltage regulation system along with Thomson's lighting
arrestor system, these combine with Brush's work made the most successful
arc light system in the world. You can see the documentary on this early
period of history via our E.W. Rice
of the Electric Light:
1890 - There were
more than 130,000 arc lamps in use in the United States.
Today the evidence of the
great number of carbon arc lamps is mostly gone. Most of the bodies
of the lamps were melted down for scrap for World War 1.
The carbon arc lamp is the root of more than 50% of all
electric lamps today as you can see in the diagram below, however
it took almost 70 years to get a reliable carbon arc lamp out of the
- Francis Hauksbee (France) builds a gas discharge lamp using an evacuated
glass tube charged with static electricity. The tube glowed faintly. 1800
- Volta (Italy) develops the first battery in the western world, this
immediately sparks a period of testing of electricity and discovery
from Russia to England. ~1800
- Vasily Petrov (Russia) first publicly describes the phenomena of
the electric arc. The year of this is not yet confirmed. ~1800 or 1809 - Sir Humphry
Davy (England) - used charcoal sticks and batteries to make the
first experimental arc lamp, the year of this is under debate. 1840s - Jean Bernard Leon Foucault
developed mechanisms for feeding carbon rods to make an arc light
last longer. 1844 - first major public demonstration
of an arc lamp in Paris 1875 - Pavel Yablochkov
- Yablochkov Candle, a form of arc lamp is developed, this lamp is
reliable and uses two carbon sticks side by side, which solves the
problem of figuring out how to keep the gap constant despite the burning
away of carbon. Mechanical feeds were not sophisticated enough yet
to be reliable. The first street lights are installed in Paris. The
arc lamp enters the commercial stage. 1876 - Charles
F. Brush, Wallace, Gramme - developed more advanced arc light
designs and dynamos to go with it. 1877 -Charles F. Brush
develops a better carbon stick by using 0.03% ash and electroplating
the rods with copper to slow the stick's consumption. 1875 - Avenue de l'Opera is
lit in Paris by Jablochkoff candles 1879
- Brush makes the first public lighting in the US at the Wanamakers
department store in Philadelphia. 1879
- Brush developed the "Brush System" in which he could run
a number of lights in series. Prior to this systems had one or a few
lights. Inventors couldn't understand why electricity changed its
properties by adding more lights, Brush understood the drop in voltage
and current although he still had no way to measure electricity. It
was later in the 1880s the importance of measurement allowed for better
and more complex electrical devices. 1879
- William Wallace improves the life of the carbon rod with a design
using copper and other ingredients. 1879 - Niagara Falls first lit
by the electric light with 16 Brush arc lamps. 1879
- Elihu Thomson built a system that could handle up to 9 arc lamps
in series with 10 Amps of current.
1880s - Elihu Thomson, Thomas
Edison, Frantisek Krizik, Nikola Tesla, E.W. Rice
- all improved the arc lamp by improving the carbon composition, mechanical
feed device, and other components. 1890s - After the end of the War
of Currents at Frankfurt, Germany
in 1891, AC systems were built across the world from Argentina to
Sweden within 10 years. Arc Lamps were adapted to run off of 110 and
220 Volt systems. 1904 - Charles
P. Steinmetz improves the lamp by replacing the carbon electrode
with magnetite, a type of iron ore. Lamp life shoots to 600 hrs or
30 hrs per inch of electrode. At the same time carbon rods only had
a max life of 125 hours (for the average carbon rod refill length) 1915 - Elmer
Ambrose Sperry develops a carbon arc spot light, first
used in Navel applications.
- The carbon arc light is used for intense spot lights and some projectors,
and is mostly replaced by xenon and metal halide lamps. The newer
lamps are superior in that they do not give off open sparks due to
having their arcs placed in a glass envelope, and they do not burn
up quickly as the carbon sticks used in carbon arc lamps.
many types of arc lamps offered by Charles Brush, taken from his company
The carbon arc lamp was first
used for street and factory lighting due to its extreme brightness which
could easily flood a large area. It was used in early film production
but proved to be dangerous to the actors. The arc lamp was used a projector
light source for some time. This light did cause fires in theaters due
to the open sparks.
The carbon arc lamp was replaced by the incandescent lamp starting in
the 1880's. It was still used for street and factory lighting into the
early 1900's. Elmer
Ambrose Sperry developed a spotlight which was used by NAVY ships
Most of the
hundreds of thousands of arc lamps and fixtures were scrapped for World
War I. Some fixtures that remained in factories were gutted out and
had sockets placed in them for the Mazda
End of the Carbon Arc Lamp Era
lamps were being phased out after the 1910s. For general lighting the
lamp was replaced by the 1920s and 30s in most cities. The lamp continued
to be used for spot lights, film production lighting and film projector
lamps. Most of the remaining carbon arc lamps ceased production by the
1980s due to the improved performance of the bright
short-arc xenon and metal halide short-arc
lamps. The new gas
discharge lamps use a glass/quartz bulb filled with a nobel gas
and other additives, they had longer life and more efficient than the
carbon arc lamp. In the new lamps gas is ionized and free electrons
smash into the additives (like metal halide) giving off photons with
the same or better quality white light.
arc lamp still exists in an extremely limited application. It is
used for a color fastness test of textiles. The lamps are part of testing
machines that use the lamp to make UV light in a controlled environment.
See one of these machines as part of the this list at Shinyei
video below shows an arc lamp working as part of a
Magic Lantern (An early projection device that would project glass slides
onto a large screen)
video below shows arc lamps in a simple street lighting setup:
worked on this lamp and we will mention the most prominent here with
a photo. The fact is there are far too many to show in this one page,
but if you are interested there are entire books about the early development
of the arc lamp. Many look back to the arc lamp days with a bit of romanticism.
At the bottom of this list we will list some others not mentioned in
the main list, however the main list with photos covers very important
people in the world of the arc lamp.
1800Sir Humphry Davy discovers the carbon arc in England
while Vasily Petrov discovers it in Russia. The exact year of
discovery is a matter of debate, it could be 1800 or 1802. England
1800Vasily V. Petrov discovers and demonstrates the
carbon arc. Both Petrov and Davy used simple systems attached
to primitive batteries.
1840sJean Bernard Leon Foucault
develops a mechanical feed device for the carbon rod, this is
an important step towards a functional, commercial product.
1875Pavel Yablochkov had developed
the Yablochkov Candle which was the first reliable carbon arc
lamp and was used in Paris. He also developed power regulation
systems, developed multi-lamp AC power circuits, and was the
first commercial success in electric lighting. See his invention
1879William Wallace develops
a copper plated carbon electrode and carbon doped with certain
materials, his work resulted in a longer lasting carbon, he
was one of many who were working on extending carbon life by
adding materials to the carbon composition. Connecticut,USA
F. Brush develops every part of the electrical system
from new lamps to better dynamos (DC) and power conditioning.
He becomes a commercial success with many installations in US
cities. Cleveland, OH, USA
Elihu Thomson develops a successful arc lamp and power
regulation system including an effective lighting arrestor. He
forms the Thomson-Houston company which grows to be the largest
company of the 1892 merger that formed the General Electric Company. Lynn, MA, USA
E.W. Rice Jr worked with Elihu Thomson, improving
many parts of the arc light system both in DC and AC power. Schenectady, NY, USA
Charles P. Steinmetz develops an arc lamp with magnetite
electrodes. This extends lamp life from 125 to 600 hours while
only sacrificing a small amount of brightness. This meant that
arc lamps needed to be "trimmed" (carbon replacement)
with the same frequency as incandescent bulbs of the time. Later
Steinmetz also invented the metal
halide lamp. Schenectady, NY, USA
Elmer A. Sperry developed a high intensity spotlight
up to 2 billion candlepower. Sperry's spotlights became vital
for naval and air warfare during WWI and WWII. Schenectady, NY, USA
Great engineer and
arc lamp innovator Elihu Thomson mentions a few other names of important
developers: Wallace Farmer, Weston, Wood, Hochhausen, and William Stanley
who developed Westinghouse's arc lamp knowledge.
are MANY others who helped develop the carbon arc lamp in many nations
of Europe and North America between 1805 - 1915. Above we have listed
the most prominent names, even so it was difficult to choose. History
is a complex matter, the deeper you dig, the more ambiguity you find.
If your interested in getting more detail about the fascinating history
of the arc lamp we recommend book: A History of Electric Light and Power
by B. Bowers and Men and Volts by John Hammond
Xenon Short-Arc Lamp
The carbon arc lamp was replaced
by the xenon short-arc lamp for many applications. The lamp makes an
arc through ionized xenon gas in a very high pressure bulb. The high
pressure give the lamp high efficiency. The light is highly intense
and close in frequency to that of sunlight.The xenon arc lamp has the
advantage over carbon arc lamps in that it does not need to be supplied
with anything(like the rods), it does not flicker, it is more compact,
and is less of a fire hazard because of having the arc enclosed.
The lamp is not safe
for technicians, the extremely high pressure (440 psi / 3040 kPa) makes
it similar to a small grenade if broken. Glass and metal shrapnel have
killed and injured people who dropped or ruptured the lamps on installation.
Injuries extend to the less-than-intelligent playing with the lamps
(see the carnage here
Ratings: 900 W - 15
kW Materials: Tungsten, molybdenum, ultra pure synthetic fused silica
(Suprasil), Invar alloy Inventor: please contact us if you know
The lamp was invented in
the 40s and was in commercial use by the 1950s as a film projector lamp.
The lamp was developed by Osram. If you know the inventor/s of this
bulb and have a photo please let us honor them by contacting
a large xenon arc lamp used in modern Imax projectors. Photo:
Right: A small xenon short arc bulb within plastic protective
housing. Instructions say do not remove the housing until after
the lamp is installed.
another video of different sized xenon short arc lamps here
(this video is not an Edison Tech Center video so the resolution/quality
Help us edit and add to this page by becoming a ETC volunteer!
Give us feedback on this and other pages using our Facebook
by M. Whelan with additional
research by Rick DeLair
Please contact us if you are a historian and wish to correct or improve
The General Electric Story: A Heritage of Innovation 1876-1999, 1999,
by the Hall of Electrical History Publication
Wikipedia, www.debook.com: "A Short History of the Electric Light"
by Frank Andrews
and Volts" by John Hammond 1941,
illustrations part of the Thomson-Houston catalogue, at the Schenectady
Wikipedia "Super Trouper" light, Xenon Short-Arc Lamp
The Iron Trade Review. August 1909
Carbon Arc Basics by Samuel Goldwasser and Don Klipstein 1996
The Electrician, June 17, 1904
Term "Subdivision of the Electric Light" by Elihu Thomson. Electrical
The Subdivision of the Light by Unknown
"Development of Arc Lighting" by Elihu Thomson. Electrical World
Vol. 80 No. 11 Sept 1922
The Edison System Forty Years Ago by Etienne de Fodor. 1921
Edison Tech Center
Michael Spadafora (Arc Lamp Collector)
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