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Preconditions to Edison's Lamp: Bracketed information [xxx] does not appear on the label.
[Label xL1 - Henry Magnet] [Curator's note, March 2003: The Henry magnet was not originally part of Lighting A Revolution, but instead served to introduce visitors to the three exhibitions that made up the Hall of Electricity in 1979. In addition to Lighting, these were Person To Person (telephone history) and First Views (static electricity). As Person To Person had closed in 1989 and we knew that First Views would be closing in 2002, we decided to refurbish the area around the Henry magnet and tie it more closely to Lighting.] [Curator's note, November 2003: The area around the Henry magnet was again refurbished in mid-2003 during work associated with the exhibition America On The Move.] "With this magnet I can lift a thousand pounds." Joseph Henry pioneered the development of powerful electromagnets, which turned out to be central to the practical use of electricity in the 19th century. They were essential for the development of motors, generators, the telegraph, the telephone, and many measuring instruments. Henry became the first Secretary of the Smithsonian in 1846, a post he held for 33 years. Object:
Graphics:
[Curator's note, November 2003. The following text was added to this label during the 2003 renovation.] Electrical Collections at the Smithsonian To document the history and social influences of electrical science and technology, this museum has preserved thousands of objects, pictures and documents. These are available for research purposes and for exhibitions, both here and through loans to other museums. Currently, two electrical topics are treated in this museum–lighting (to your left) and communications (in the Information Age exhibition elsewhere on this floor). More can be found on the museum's website.
[Label xL105 - Title header]
LIGHTING A REVOLUTION
[xLOT2: hanging sign] [Curator's note, March 2003: First Views was de-installed in May 2002 as part of the space-preparation process for the exhibition America On The Move.] FIRST VIEWS
[xLOT3: hanging sign] [Curator's note, November 2003. This sign was removed during the 2003 renovation.] LIGHTING A REVOLUTION
[xLOT4: hanging sign] [Curator's note, November 2003. This sign was removed during the 2003 renovation.] Exit from
[Label xL5 - Introduction to Exhibit] "Well, I'm not a scientist, I'm an inventor." Of course, some scientists are also inventors. But there is a difference. A person acting scientifically is trying to understand the natural world, whether or not that understanding is economically useful. An inventor tries to create something new that will have practical application. In both cases there is a sense of challenge in the pursuit and a sense of achievement in the result. In this exhibition we will see how inventors work, and whether they act today the way Edison did a century ago. We will look at 1) Preconditions for invention We will look first at Edison's work on the incandescent light in the late 19th century, and then at several other lighting inventors a hundred years later. We will also see how concepts of efficiency have come to dominate the lighting field. Edison at his West Orange laboratory in 1906 at age 59.
[xL5.1: introduction to webnotes] An expanded version of this exhibit can be found on-line. Webnotes refer to specific places on the website for citations and more detailed information. To use them, go to the website and click on the Webnotes link. The URL for this site is [Label xL6 - Exhibition Credits] This exhibition is a collective effort by staff of the National Museum of American History and the Smithsonian Institution. Historical exhibitions are complex undertakings, and the history they present is an interpretation of historical evidence informed by knowledge and experience. This exhibit opened originally in 1979 and featured only Edison's activities. In 2000 it was modified to include recent developments and to make comparisons -- to see how invention has changed, and how it has stayed the same. The original Lighting a Revolution exhibit was curated by Bernard Finn with assistance from Robert Friedel and Cathy Zusy; the designer was David Ellis; editing was by Michael Fruitman; production was by the Museum's Exhibits staff. Funding came from a major grant from the International Committee for the Centennial of Light of the Thomas A. Edison Foundation and General Electric's Lighting Business Group. The additions and revisions were inspired by the vision of Dr. Lee R. Anderson (1936-1998), Lighting Program Manager at the Department of Energy. The new section was curated by Bernard Finn with assistance from Harold Wallace; the designers were David Ellis, Marcia Powell, Constantine Raitzky, and Russell Cashdollar; editing was done by Nancy Growald Brooks; project managers were Patrick Ladden and Andrew Heymann; production was by outside sources; and the website was produced by Harold Wallace. Funding came from a major grant from the United States Department of Energy, and additional grants from a fund in memory of Carl Weller, and from Eveready Battery Co. Inc. Lighting fixtures provided by Lightolier, lamps provided by OSRAM SYLVANIA Inc. [Label xL7.1 - Section #1 introduction - Edison free-standing cut out] Step 1: Preconditions
[Label xL7.2 - Section #1 introduction - Edison free-standing cut out] "Mr. T. A. Edison has resigned his situation in the Western
Union office, Boston, Mass., and will devote his time to bringing
out his inventions." Edison had very little formal education, but he read extensively. A practicing telegrapher from 1862 to 1868, he gained hands-on experience with electrical apparatus. This gave him the confidence he needed to strike out on his own. Edison in 1861 at age 14.
[Label xL8 - Batteries] Batteries Italian Alessandro Volta announced in 1800 that he could produce electricity by chemical means. His pile or "battery" stimulated a wide number of scientific and technical experiments. Note in particular the early voltaic pile (1) and the early trough battery (2) designed by William Cruickshank in England following Volta's principles. Modifications of the Daniell cell were widely used in American telegraphy.
Webnote: 1-3
[Label xL9 - Motors] Motors In 1821 in England, Michael Faraday discovered a way to change electrical energy into the continuous motion of a motor in 1821 Others followed with their own variations. Note in particular the design (6) by Thomas Davenport, a Vermont blacksmith, who in 1834 had all the essential elements of the classic motor -- a rotating armature, field magnets, and a commutator.
Webnote: 1-4
[Label xL10 - Generators] Generators Working at the Royal Institution in London, Michael Faraday felt certain that somehow magnetism could produce electricity. After a decade of searching, he found the answer in 1831. It was a simple matter of having a conducting wire move across the "lines of force" that Faraday imagined coming out of the end of the magnet. Early machines were very weak because they depended on permanent magnets. Note in particular the early Pixii machine (14), with a commutator (to change alternating to direct current) designed by A. M. Ampere. The Holmes-type machine (17), with its several large permanent magnets, was inefficient but still strong enough to light arc lamps for special applications. In 1866 Charles Wheatstone and Werner Siemens independently invented the self-excited generator (18), where the magnetic field is produced by an electromagnet using electricity from the generator itself. In just a few years very efficient generators were being designed, most notably by Zenobe Gramme (19).
Webnote: 1-5
[Label xL11 - Meters] Meters It is necessary to measure electrical effects in order to perform scientific and technical experiments. All of these meters operate on the principle that a magnet will move when affected by an electric current. Note in particular the Nobili galvanometers (21, 22). There are two magnetized needles attached to the vertical string, parallel to each other but magnetized in opposite directions, which means that the combination is not affected by the Earth's magnetic field. One you can see above the coil, and the other is inside the coil. When current flows in the coil, the needle inside is affected more, and it twists the string. You can see how much it twists by looking at the upper needle.
Webnote: 1-6
[Label xL12 - Electromagnets] Electromagnets The electromagnet was arguably the most important electrical invention of the 19th century. It concentrated the magnetism produced by electricity and made it possible to build effective telegraphs, telephones, generators, and motors. William Sturgeon constructed the first practical electromagnet in 1824 in England. Joseph Henry, an American, perfected the design. Note in particular the magnet Henry constructed for Yale University at the entrance to this hall, as well as the cores for some of his earlier magnets shown here (28, 29, 30)
Webnote: 1-7 [Curator's note, November 2003. New label added during 2003 renovation] Faces of Invention Many people shared Edison's
ambition and passion to invent. Amid fierce
[Label sL1 - Weston] Edward Weston (1850 -1936) Weston emigrated from England to Newark, New Jersey, in 1870. He established the Weston Electric Instrument Company there in 1888. Its meters gained a reputation for accuracy and reliability.
[Label sL2 - Gramme] Zenobe-Theophile Gramme (1826 -1901) Gramme, a Belgian, used Pacinotti's armature design to make efficient magneto generators in the 1860s and self-excited dynamos in the 1870s.
[Label sL3 - Pacinotti] Antonio Pacinotti (1841 -1912) Born in Pisa, Italy, Pacinotti became professor of physics at the University of Bologna at age 23. There he developed a ring armature design that was used by Gramme in motors and generators.
[Label sL4 - Barker] George F. Barker (1835 -1910) A professor of Physics at the University of Pennsylvania from 1835 to 1900, Barker was Edison's closest friend in the academic community. His interest in electric lighting was an influence on Edison in 1878.
[Label sL6 - Brush] Charles F. Brush (1849 -1929) Trained in chemistry at the University of Michigan, Brush established himself in Cleveland. There he built his first dynamo in 1875 and an arc light in 1876. His company eventually became part of General Electric.
[Label sL7 - Houston] Edwin J. Houston (1847 -1914) Houston was born in Alexandria, Va., but spent most of his life in Philadelphia teaching at Central High School. With Elihu Thomson, he designed an arc-light generator. He left the Thomson-Houston Company in 1882 to devote his time to teaching.
[Label xL13 - arc lamp information and credits]
Arc Lamps
"The intense light had not been subdivided
so that it could be brought into private houses." In an arc light, vaporized carbon particles are heated electrically to the point where they glow brightly--too bright in fact for use in the home. Edison proposed to use electricity to heat a wire. The brightness of this "incandescent" lamp could be made dim enough for use indoors. Electricity does not flow freely through materials. This resistance to the flow can vary, depending on what is in the circuit, or path, of the flow of electricity. Arc lights had low electrical resistance. In a circuit several were linked together in electrical series, and their total resistance was high compared to the resistance of the conducting wires. Thus more energy was used in the lights and not wasted as heat in the wires. Edison s successful incandescent lamp had a relatively high resistance and could be controlled individually.
Webnote: 1-8
[Curator's note,
November 2003. This
label was changed during the 2003 renovation. The following is the
original text of the label.]
Arc Lamps "The intense light had not been
subdivided so that it could be brought into private houses." In an arc light, particles of vaporized carbon are heated electrically to the point where they glow brightly--too bright for use in the home. Edison proposed to use electricity to heat a wire (he was thinking of platinum or some other metal but eventually settled on carbon). The brightness of this incandescent lamp could be made dim enough for use indoors. Furthermore, arc lights had low electrical
resistance (a few ohms). In a circuit several were linked together
in series so that their total resistance was appreciable compared
to the resistance of the conducting wires; thus more energy was
used in the lights and not wasted as heat in the wires. Edison s
successful incandescent lamp had a relatively high resistance (about
100 ohms) and could be controlled individually.
[Label xL14 - Arc-lamp generators]
"Hurry up the machine, I have struck a bonanza." Edison had ordered a generator, like the one in the smaller case
behind you, from William Wallace the previous week. He was anxious
to use it in his experiments.
The development of efficient electric generators in the early 1870s made the commercial use of arc lamps possible. The first large-scale application occurred in Paris in 1878, with lamps designed by Russian inventor Paul Jablochkoff and generators by the Belgian Zenobe Gramme. In America, Wallace (with Moses Farmer), Charles Brush, and the firm of Elihu Thomson and Edwin Houston soon followed with their own systems. But bright arc lamps were not suitable for use inside. Edison thought he saw a way to make smaller lights. He called this idea his "bonanza." At left:
Graphics: A. Arc lighting in Paris (1878) [Curator's note, November 2003. This label was changed during the 2003 renovation. The following is the original text of the label.] "Hurry
up the machine, I have struck a bonanza." Edison had ordered a generator like the one in the large case to your left from William Wallace the previous week. He was anxious to use it in his experiments. The "bonanza" was his notion that he would subdivide the brightness of the arc light and have many separately controlled lamps. Arc lamps
became practical with the development of machines that could function
as stable power-sources machines like the Thomson-Houston generator
in the case behind you. The first commercial form of electric lighting,
arc lamps are very bright and well suited for lighting large areas.
[Label sL5 - Jablochkoff] Paul Jablochkoff (1847 -1894) Born in Russia, Jablochkoff spent his career in Paris. There he invented an "electric candle" arc light in 1877, which was sensational in demonstrations in theaters and opera houses.
[Label xL102 - Wallace generator]
Generator by William Wallace, 1877 [181,644], from Coe Brass Manufacturing
Company
[Label xL103 - Thomson-Houston generator]
Generator by Elihu Thomson -Edwin Houston, 1987 [181,717], from
General Electric Company
[Curator's note,
November 2003. This
label was removed during the 2003 renovation, along with the London
and Paris Hippodrome images.]
[L15 - arc lamp photos label]
"I believe I can beat you making the electrical light." By the mid-1870s Americans William Wallace, Charles Brush, and
other inventors had made small-scale arc light demonstrations. The
first large-scale application occurred in March 1878 when Jablochkoff
arc lamps, powered by Gramme generators, lit the streets of Paris.
Edison proposed to make an incandescent lamp that was not as bright
and could be operated individually.
Photos on right, top to bottom, show arc lighting in London (1879),
in Paris (1878), and inside the Hippodrome in Paris (1880); on right,
Military Academy at West Point (1879).
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