Heinrich Göbel

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Henry Goebel, first published photo January 1893

Heinrich Göbel, later Henry Goebel (April 20, 1818 – December 4, 1893), born in Springe, Germany, was a precision mechanic and inventor. He emigrated in 1848 to New York City and lived there until his death. In 1865 he received the American citizenship.

In 1893 the public in the USA and in Europe took notice of Henry Goebel. Magazines and newspapers reported that Henry Goebel had developed incandescent light bulbs comparable to those invented in the year 1879 by Thomas Alva Edison 25 years earlier. Henry Goebel did not apply for a patent.

In 1893 the Edison Electric Light Co. brought suit against three manufacturers of incandescent lamps for infringing Edison´s patent. The defense of these companies claimed the Edison patent was void because of the same invention of Henry Goebel 25 years earlier (Goebel-Defense).

Judges of four courts raised doubts; there was no clear and convincing proof for the claimed invention of Henry Goebel. A research work published in 2007 concluded that the Goebel-Defense was fraudulent.[1]

After the death of Henry Goebel, in some countries, the legend came into being that he was the true inventor of the practical incandescent light bulb.

Biography[edit]

Springe, Germany 1818 - 1848[edit]

This house was believed to be the birthplace of Henry Goebel. Heinrich Göbel lived in this house in the 1840s, but it is not his birthplace. At the front side of this house an incandescent light bulb is burning day and night.[2]

On April 20, 1818 Heinrich Göbel was born in Springe near Hanover in Germany. His father, Heinrich Christian Göbel, was a gardener and later a door-to-door salesman for chocolate. The name of his mother was Marie Eleonore née Hüper. At that time Springe was a small village in the Kingdom of Hanover with less than 2.000 inhabitants. Most of them worked in agriculture.

1832 Henry Goebel finished school with bad results. His teacher added this comment: "He seems to have an inventive mind. The reasons of the poor marks appear to be in his lengthy illness."

In 1834 master locksmith Gerhard Linde of Springe admitted Henry Goebel as an apprentice for 3 years. It is not known whether Henry Goebel finished this training.

1837 he started to work as a repair mechanic on markets. Later in New York he gave 1837 as the foundation date of his business.

In 1844 Henry Goebel married Sophie Lübke née Rodewig. In the documents he gave watchmaker as his profession at that time. There are no sources to confirm a training as watchmaker. Probably Goebel learned by doing and did work comparable to a precision mechanic. He operated a one person business repairing clocks. His son Johann Carl was born 1846, and his daughter Marie Sophie in 1848.

In 1848, at the age of 30, Henry Goebel and his family emigrated to New York City. They left Germany in 1848 on the sailing ship "J.W.Andrews" and arrived in New York in January 1849. According to the list of passengers of the ship, he gave "mechanic" as his profession. The reasons for emigration are not known.

New York 1849 - 1893[edit]

Goebel-Lamp No. 5. This lamp was at exhibition in Goebel's shop April 29, 1882
Goebel-Shop in New York, Grand Street. Probably this photo was taken in the year 1893 to support the Goebel-Story. The telescop which Henry Goebel used in the 1850s on a horse wagon was much larger.

In New York Henry Goebel opened a shop in Monroe Street. The title was Jewelry, Horology and Optician's Store.

To earn more money, Henry Goebel constructed a telescope. Frequently in the 1850s and 1860s he moved with his large telescope on a horse wagon to Union Square in the evening and by payment of a fee people could use his telescope to observe the stars. In litigations of the year 1893 many persons remembered the telescope-man.

On May 9, 1865 Henry Goebel obtained the U.S. Patent No. 47.632 "Hemmer for sewing machines." Probably he got the idea when thinking about how to make the sewing work of his daughter more easy. He was not successful in selling the patent.

1872 Goebel moved his shop to Grand Street.

In 1881 Henry Goebel worked as a kind of consultant for the American Electric Light Co. Obviously there was a need for precision mechanics for the construction of electric lamps. Furthermore, he produced carbon filaments in his shop for the company.

He finished this work after half a year and tried to start his own business in the field of incandescent light bulbs together with his friend John Kulenkamp. Both were members of a Lodge of Freemasons of German immigrants.

On April 30, 1882 the New York Times reported about an exhibition of incandescent light bulbs in Goebel's shop. According to this report Henry Goebel told the story, that the electric light was by no means as new an invention as it was popularly supposed to be and that he knew this kind of light since his time in Germany. He affirmed that he produced electric lights since the 1850s without giving technical details. The lamps at exhibition were incandescent light bulbs with carbon-filaments of high resistance made of fibres of reed.[3]

Two patents were granted to Henry Goebel in 1882, an improvement of the Geissler-System of vacuum pumps and a solution to connect carbon-filaments and metal-wires in a light bulb.

In 1882 Goebel made an offer to sell his inventions to the Edison Electric Light Co. for a few thousand dollars, but Edison did not see enough merit in the invention to accept the offer.

Obviously Henry Goebel and his friend John Kulenkamp were not successful in starting a business.

In the 1880s some patent attorneys visited Henry Goebel because of the report in the New York Times 1882. They were interested in early incandescent light bulbs to move Edison's patent of 1880 into question. Later they said, there was not much evidence, and Henry Goebel was not able to present old lamps.

In 1887 Henry Goebel's wife Sofie died. At least 8 more children of them were born in the USA. 7 children survived both parents.[4]

In the late 1880s Henry Goebel retired and his son Henry Goebel Jr. became the owner of the shop.

In 1893 Patent attorneys Witter & Kenyon, New York, became the counsels of the defense in three cases of patent infringement. Henry Goebel became the main witness of the defense in these cases. His story of 1882 was used to create the Goebel-Defense.

Henry Goebel died on December 4, 1893 because of pneumonia. He was buried at Green-Wood Cemetery.

The lawsuits with the Goebel-defense continued until May 1894.

The work for the American Electric Light Co. 1881, the patents from 1882 and the report in the New York Times from April 30, 1882 are the earliest clear sources for work of Henry Goebel related to incandescent electric light bulbs. No earlier source is known to prove any kind of relation to incandescent light bulbs or any kind of work in the field of electricity. Doubtful details of the biography of Henry Goebel given by himself are not listed.

The claimed Goebel anticipation concerning Edison's incandescent light bulb patents[edit]

The Litigations with Goebel-Defense in 1893 and 1894[edit]

Decisions in the suits with Goebel-Defense
Feb. 18, 1893 Beacon Vacuum Pump and Electric Company, Boston, preliminary injunction granted (Judge Lebaron B. Colt)
Apr. 21, 1893 Columbia Incandescent Lamp Company, St. Louis, preliminary injunction denied (Judge Moses Hallett)
Jul. 20, 1893 Electric Manufacturing Company, Oconto, preliminary injunction granted (Court in Milwaukee; Judge William H. Seaman)
Jan. 26, 1894 Philadelphia Trust Co., Manufacturers' Club of Philadelphia und Spreckels Sugar-Refining Co., preliminary injunction granted, Philadelphia (Judge Acheson)
May 9, 1894 Electric Manufacturing Company, Oconto, preliminary injunction confirmed, appeal, (Court in Chicago; Judge James G. Jenkins)
Jan. 11, 1895 Philadelphia Trust Co, Philadelphia, preliminary injunction confirmed, appeal, (Judge Wales)
no final hearing
Nov. 19, 1894 Expiry date of US Patent 223.898 of the Edison Electric Light Co. (since 1893 General Electric); Patent applied November 30, 1879/ granted January 27, 1880
Drawing of Goebel-Lamp No. 1. Source: Affidavit Henry Goebel January 21, 1893
Goebel-Lamp No. 4. Henry Goebel said, he had made this lamp prior to 1872. This lamp was considered to anticipate the Edison patent, assumed the date of production was fully proved. Goebel-Lamps No. 1,2 and 3 were subject of technical discussions whether they anticipate the invention of Thomas Edison.
Tools for the production of thin carbon-filaments, presented at court 1893. Henry Goebel affirmed the construction and usage of these tools in the 1870s.

In 1892 the litigation Edison Electric Light Co. vs. United States Electric Lighting Co. from 1885 came to a final decision. The court confirmed the patents of Thomas Edison related to the incandescent light bulb.

Based on this decision the Edison Electric Light Co. brought suits to obtain preliminary injunctions to close the productions of incandescent light bulbs of the Beacon Vacuum Pump and Electrical Company, Boston, the Columbia Incandescent Lamp Company, St. Louis and the Electric Manufacturing Company, Oconto, Wisconsin.

Patent attorneys Witter & Kenyon, New York, became the counsels of the defense in all three cases. They declared Edison's patents void because it was not a novelty in 1880. Their witness Henry Goebel made a claim, back in 1854, he had designed the first practical incandescent electric light bulb. He said, he had used his lamps for personal purpose without applying for a patent. The counsels called this an "overseen invention". Henry Goebel was an unknown person at that time.

Goebel's main evidence was witnesses, which US patent courts discounted. Goebel himself was the most important witness of the defendant companies. Patent attorneys Witter & Kenyon worked out an extensive defense with several hundred pages of affidavits. So-called Original Lamps were presented at court. Witnesses said they existed earlier than 1880. Furthermore so-called Reproduced Lamps were presented at court. Witnesses said, that Goebel had produced these lamps himself at Beacon Vacuum Pump and Electrical Company, Boston using his old tools. In 1893 Henry Goebel was at the age of 75. He said that he had lost a lot of lamps and tools for the production of lamps when he left his shop in New York years ago.

In the case Edison Electric Light Co. vs. Columbia Incandescent Lamp Co., St. Louis 181 persons supported the Goebel-Defense providing affidavits and 142 persons supported the Edison view.[5] The view of the Edison Electric Light Co. was that Henry Goebel didn't built practical incandescent light bulbs before 1880. The counsels of the Goebel-Defense didn't provide any documentation or convincing proof which could be dated without any doubt to a time earlier than 1880, the year the patent was granted to Thomas Edison.

Many persons providing affidavits in 1893 said that they had seen the electric lamps of Henry Goebel in the 1850s to the 1870s. Henry Goebel used his lamps according to these affidavits for the advertizment of his shop in New York and for the advertizment of his telescope at Union Square, New York. Members of Goebel's family and friends of them affirmed the usage of incandescent lamps in the daily life of the family before the year 1880. The most surprising story for the public was the alleged usage of incandescent lamps for the advertizment of Goebel's telescope in the center of New York for years. It was said, thousands of New Yorkers had seen Goebel's lamps. Approximately 75 witnesses confirmed this in affidavits; approximately the same number of witnesses remembered oil-lamps only.

Goebel claimed his lamp contained a high resistance filament of carbon, platinum lead-in wires in an all-glass envelope, and a high vacuum produced with the Torricellian method using mercury. He tried several materials to produce the carbon filaments and discovered the advantages of bamboo. These solutions were exactly the results of the research work of the Edison Electric Light Co. and the novelties of Edison's patents.

Technical experts of both sides gave their opinion about the Goebel lamps and the claimed way of production in affidavits. Experts of the Edison side contested the quality of the lamps and the possibility to produce lamps using the affirmed procedure. Experts of the Goebel-Defense confirmed the quality of the lamps and the method of production. Witnesses of the Goebel-Defense said, that reproduced lamps burnt 45, 87 und 166 hours.[6] Edison's lamps burnt at time of applying for a patent approximately 40 hours. So-called Goebel Original Lamps were broken in 1893. Experts of the Edison side said that they never burnt.

Lewis Latimer, an employee of the Edison Electric Light Co. and responsible to support their counsels, discredited Goebel by demonstrating that his supposed 1870s bulb (Goebel Lamp No. 4) had been built much later.[7] Professor van der Weyde, an 80 years old physicist, said in his affidavit, he had seen Goebel's telescope and his incandescent lamps. Later he withdrew his affidavit. Witter & Kenyon expressed suspicions of bribery of witnesses. The newspapers reported about some turbulent phases in these lawsuits during the year 1893.

Judge Colt (Edison Electric Light Co. vs. Beacon Vacuum Pump and Electrical Company, Boston) explained how he ruled based on probabilities:

It is extremely improbable that Henry Goebel constructed a practical incandescent lamp in 1854. This is manifest from the history of the art for the past fifty years, the electrical laws which since that time have been discovered as applicable to the incandescent lamp, the imperfect means which then existed for obtaining a vacuum, the high degree of skill necessary in the construction of all its parts, and the crude instruments with which Goebel worked.

It has often been laid down that a meritorious invention is not to be defeated by something which rests in speculation or experiment, or which is rudimentary or incomplete. The law requires not conjecture, but certainty. It is easy after an important invention has gone into public use for persons to come forward with claims that they invented the same thing years before, and to endeavor to establish this by the recollection of witnesses as to events long past. Such evidence is to be received with great caution, and the presumption of novelty arising from the grant of the patent is not to be overcome except upon clear and convincing proof.[8]

The opinion of Judge Hallett in the case Edison Electric Light Co. vs. Columbia Incandescent Lamp Co., St. Louis:

It is said that Goebel is involved in contradictions and misstatements of fact, due to the lapsing memory of old age, or to untruthfulness. Be it so. He does not appear to be an adventurer or an impostor. It is not reasonable to believe that he made the story related in his affidavit, and did not make the lamp he has described. Whatever may be said as to Goebel's veracity, he is supported at many points by witnesses of good repute, who speak with precision, and apparently with deliberation. …I need not refer to the possible effect of cross-examination in the case of a multitude of witnesses. What now seems plain enough may altogether disappear, and new facts may come to the surface under that crucial test."[9]

The opinion of Judge Jenkins in the case Edison Electric Light Co. vs. Electric Manufacturing Co., Oconto was based on the last development of the Goebel-Defense with new affidavits and withdrawn affidavits in May, 1894:

Without assuming to say that the story of this invention is untrue, and without designing to suggest what result should be reached upon final hearing, we are compelled to say that the story is surrounded by such an atmosphere of improbability that, until it shall have been thoroughly sifted and sustained upon final hearing, the claim ought not to be permitted to invade the monopoly accorded to, another for the same invention, whose claim has passed safely the ordeal of judicial scrutiny.[10]

A decision, whether the Goebel anticipation was held true or untrue, required a final hearing, but there was never a final hearing in the litigations using the Goebel-Defense. It was the responsibility of the Edison Electric Light Co. to move the case in St. Louis to a final hearing. Probably they did it not because of the expiry date of Edison's patent in 1894 and high cost.

It is not sure, that the proof of the alleged anticipation was the true strategy of the counsels of the defense. Perhaps the aim of the extensive Goebel-Defense was to avoid a decision of a final hearing before the expiry date of Edison's patent. This was successful in the case of the Columbia Incandescent Lamp Co. The company produced lamps without interruption though they never proved the invalidity of Edison's patent.

In two cases the preliminary injunction was granted, in one case the injunction was denied. In Philadelphia another injunction was granted in a suit filed by the Edison Electric Light Co. to stop the usage of patent infringing lamps at some companies. The counsels of the defense in this case used the arguments of the Goebel-Defense.

The point of controversy in these lawsuits between the Edison Electric Light Co. and their competitors was money. It was not a controversy about the honor to be the inventor of the incandescent light bulb. There was no benefit for Henry Goebel in these suits. He said, he was not interested in the decisions of the courts and that he had no hostile mind towards Thomas Edison. In an affidavit he said he got no money for providing details of his work concerning incandescent lamps.

Historical extrajudicial investigations and views on the anticipation claim[edit]

During the litigations most newspapers reported with a neutral point of view, but some raised doubts about the alleged Goebel anticipation.

"A romantic story of the poor inventor Goebel which will be forgotten soon" was the commentary of a technical magazine in Germany.[11]

The journalist A.M.Tanner from London visited Springe, Goebel's native town, and interviewed some people there. In his article published in The Electrical Review in February 1894 we wrote, that nobody had confirmed the alleged work of Goebel related to electricity before leaving Germany. Tanner reported, Goebel's alleged teacher in the field of electricity and electric lamps, Professor Münchhausen, was an unknown person in Springe and Hanover. Goebel said in one of his affidavits, that he had learned the professions of a watchmaker and an optician. In Springe Tanner got the information, that Goebel had learned the profession of a locksmith.[12]

Investigations of recent years[edit]

Investigations in recent years partially confirmed the article of Tanner.

One important point is, that there is no source to confirm Goebel's alleged source of knowledge in the fields of electricity and vacuum physics. Goebel claimed that he had worked together with a certain Professor Münchhausen in the 1840s, that he had constructed equipment for experiments at today's University of Hanover ( at that time called Höhere Gewerbeschule), that he had assisted experiments related to electric light, that he had got the idea and the basic concept of the design of an electric incandescent lamp from Professor Münchhausen and that he had continued with experiments on electric light on his own in New York. A person Professor Münchhausen was not known in the Kingdom of Hanover in the 1830s and 1840s, there is no documentation of experiments on electric light in the Kingdom of Hanover in the 1840s and no source for deliveries of equipment or any other kind of relation of Henry Goebel to today's University of Hanover.

As one result of investigations in Germany and in the USA and an analysis of all documents of the litigations with Goebel-Defense Hans-Christian Rohde stated in his dissertation, that there is no source from the time prior to 1880 to support the assumption of a relation of Henry Goebel to incandescent lamps prior to 1880.[13] His thesis is, that Henry Goebel got the knowledge when working for the American Electric Light Co. in 1881 and was not busy with incandescent lamps before.

A philological analysis of all affidavits of the Goebel-Defense manifested numerous contradictions and improbabilities. This and the lack of independent sources in the archives to confirm claims of Henry Goebel support the thesis, the Goebel-Defense was fraudulent. Probably Goebel told his story in 1882 to present himself as experienced in the art of construction of electric lamps to promote his intended business. Patent attorneys and their technical consultants created the Goebel-Defense on base of this story.[14] Probably a biography of an inventor of electric light was constructed on top of the true biography of Henry Goebel. There is circumstantial evidence that falsification of written affidavits was part of the strategy of the counsels of the defense.[15]

One curious matter is the name of Goebel's alleged teacher, Professor Münchhausen. Münchhausen is a rare family name in Germany and Münchhausen is the name of a literary figure in a collection of tales with title The Surprising Adventures of Baron Munchausen of Rudolf Erich Raspe (published 1785) and in another version of Gottfried August Bürger (published 1786), a popular book in Germany; a man telling lies and incredible stories. A thesis on this is, that Henry Goebel, an old man, was under pressure of lawyers to provide affidavits and got pangs of conscience and this was his way to indicate the story was untrue. In the culture of Germany there is a close association of "Münchhausen" and "untrue, telling lies".[citation needed]

So-called Goebel Original Lamps are in the archives of the Henry Ford Museum, Dearborn. A technical examination with today's methods of science to establish, if possible, a final truth on the production year of the lamps and to clear up technical points of dispute in the litigations did not take place yet.

The Goebel-Legend[edit]

Monument to the honor of Henry Goebel in Springe, Germany (native town). Constructed 1954, the believed 100. anniversary of his invention
Monument from 1954 in honor of Heinrich Göbel, the "inventor of the electric light bulb". Death date on the monument is December 16, 1893. The Electrical World reported the death of Henry Goebel at December 4. In Germany, December 16 was reported to be the date of his death in an important article about Goebel 1923. This is the reason for the wrong date of death as well in the inscription as in many other published documents in several countries.

Franklin Leonard Pope was a close friend of Thomas Alva Edison but later he was in quarrel with him.

He was an important man with a good reputation in the field of electricity; in 1886 he was the President of the American Institute of Electrical Engineers.

In January 1893 Franklin Pope wrote an article published on the head page of the Electrical Engineer titled The Carbon Filament Lamp of 1859—The Story of an Overlooked Invention.[16] In this article Franklin Pope credited the invention of the practical incandescent light bulb to Henry Goebel. Furthermore he supported the Goebel-Defense at court providing affidavits.

Probably his relationship to Thomas Edison was the motivation of Franklin Pope.

The reputation of Franklin Pope and his article in The Electrical Engineer is the reason for the existing view in some countries that Henry Goebel developed a carbon filament lamp many years before Thomas Edison did it. The Electrical Engineer is available in the libraries of many technical universities. Franklin Pope´s article was interpreted as a reliable source as well in the year of publishing as in later years. In 1893 his article was the source for reports about the Goebel-Story of newspapers in the USA and in Europe.

As a matter of fact there is a lack of convincing evidence for the information about the lamps of Henry Goebel given by Franklin Pope in his article. This was the result of the litigations (motions for a preliminary injunction) in three cases in 1893 and 1894.

In a dissertation published 2007 it is stated, that the article was part of the fraudulent Goebel-Defense and the intention was to produce credibility for the Goebel-Story and sympathy for Henry Goebel, an „underdog" who anticipated the famous Thomas Edison. According to this view, Franklin Pope was a fraudulent acting consultant of the Goebel Defense.[17]

Franklin Pope wrote a book titled Evolution of the Electric Incandescent Lamp. In the 2nd Edition of this book, published 1894 one year after his article about Henry Goebel in the Electrical Engineer of January 1893, Henry Goebel is not mentioned.[18]

In the case Edison Electric Light Co. vs. Columbia Incandescent Lamp Co. Judge Moses Hallett denied the granting of a preliminary injunction. His opinion was, that a final hearing with all witnesses at court was necessary. Several magazines and newspapers stated that Judge Hallett believed Goebel's lamp preceded Edison's. In Germany the opinion of Judge Hallett was reported to be a final decision in the case. Sometimes it wasn't realized that the litigations were three independent cases with the same counsels of the defense using the same arguments. Due to this erroneous view the later decision of Judge Hallett was reported as a decision of a higher court in the same case. That are misstatements of Judge Hallett's decision, and the source of the legend that the priority of Henry Goebel for the invention of the practical incandescent light bulb was established at court.

After his death, Henry Goebel had been forgotten for 30 years in Germany. In the year 1923 the story of an important national inventor was created; the report of Franklin Pope was the main source.[19] Some other countries adapted the story from Germany in the 20th century. Additional misstatements became part of some versions of the legend. For example, some versions of the legend describe the first Goebel lamps as bottle-lamps. But Henry Goebel said that he had melted the glass of Eau-de-Cologne-Bottles with a blowpipe to produce the all-glass-envelope of his very first lamps in the 1850s.

Different views became obvious due to the internet and some projects in the USA and in Germany started investigations in the year 2000 and later. As a result, the assumption of Goebel lamps prior to 1880 without any doubt was named a legend.

US-Patents granted to Henry Goebel[edit]

  • Patent 47.632 „Hemmer for Sewing Machines", May 9, 1865[20]
  • Patent 252.658 „Vacuum Pump (Improvement of the Geissler-System of vacuum pumps", January 24, 1882[21]
  • Patent 266.358 „Electric Incandescent Lamp (sockets to connect the filament of carbon and the conducting wires)", October 24, 1882[22]

See also[edit]

References[edit]

  1. ^ Hans-Christian Rohde: Die Göbel-Legende – Der Kampf um die Erfindung der Glühlampe. Zu Klampen, Springe 2007, ISBN 978-3-86674-006-8
  2. ^ Hans-Christian Rohde: Die Göbel-Legende, p. 96
  3. ^ The New York Times: A NEW INCANDESCENT LIGHT. A GERMAN ELECTRICIAN'S INVENTION April 30, 1882
  4. ^ Henry Goebel. In: The Electrical World, Vol. XXI, No. 18, May 6, 1893, p. 332
  5. ^ Hans-Christian Rohde: Die Göbel-Legende, p. 41
  6. ^ The Columbia Incandescent Lamp Company Case. In: The Electrical World, Vol. XXI, No. 16,April 22, 1893, p. 294
  7. ^ Fouché, Rayvon, "Black Inventors in the Age of Segregation: Granville T. Woods, Lewis H. Latimer, and Shelby J. Davidson." The Johns Hopkins University Press, Baltimore & London, 2003, pp. 115–116. ISBN 0-8018-7319-3
  8. ^ Federal Reporter: Edison Electric Light Co. vs. Beacon
  9. ^ Decision in the Columbia Incandescent Lamp Suit. In: The Electrical World, Vol. XXI, No. 17, April 29, 1893, p. 312
  10. ^ Federal Reporter: Edision Electric Light Co. vs. Electric Manufacturing Co.
  11. ^ Der Glühlampenstreit in Amerika In: ETZ Elektrotechnische Zeitung, 14th Year, No. 14, April 7, 1893, p. 206
  12. ^ A. M. Tanner: The Goebel-Munchhausen Lamp Story. In: The Electrical Review, Vol. 34, No. 845, February 1, 1894, p. 113, London.
  13. ^ Hans-Christian Rohde: Die Göbel-Legende, p. 69
  14. ^ Hans-Christian Rohde: Die Göbel-Legende, p. 133
  15. ^ Hans-Christian Rohde: Die Göbel-Legende, p. 73 und p. 77
  16. ^ Franklin Leonard Pope: The Carbon Filament Lamp of 1859—The Story of an Overlooked Invention. In: The Electrical Engineer, Vol. XV, No. 247, January 25, 1893, p. 77
  17. ^ Hans-Christian Rohde: Die Göbel-Legende, pp. 82–86
  18. ^ Edward Covington: A Review of the Henry Goebel Defense
  19. ^ Hermann Beckmann: Die erste elektrische Glühlampe. In: ETZ Elektrotechnische Zeitschrift – Organ des VDE, No. 47/48, November 29, 1923, pp. 1031–1034
  20. ^ Goebel's patent 47.632 „Hemmer for Sewing Machines"
  21. ^ Goebel's patent 252658 „Vacuum Pump"
  22. ^ Goebel's patent 266358 „Electric Incandescent Lamp"

Bibliography[edit]

External links[edit]