Francis Jehl (September 6, 1860 - February 11, 1941) was a laboratory assistant of

Thomas Edison Thomas Alva Edison (February 11, 1847October 18, 1931) was an American inventor and businessman. He developed many devices in fields such as electric power generation, mass communication, sound recording, and motion pictures. These inventio ...

. Jehl studied chemistry at

Cooper Union The Cooper Union for the Advancement of Science and Art (Cooper Union) is a private college at Cooper Square in New York City. Peter Cooper founded the institution in 1859 after learning about the government-supported École Polytechnique in ...

at night. After finishing school at the age of 18, he went to work for Edison at Menlo Park. In 1882, Jehl went to Europe to introduce the Edison light system in the various European countries. Jehl wrote a book titled ''Reminiscences of Menlo Park'' based on a diary of his experiences at the laboratory.

History

Before Jehl worked for Edison he worked for Grosvenor P. Lowrey, who was the chief counsel of

Western Union Telegraph Company The Western Union Company is an American multinational financial services company, headquartered in Denver, Colorado. Founded in 1851 as the New York and Mississippi Valley Printing Telegraph Company in Rochester, New York, the company chang ...

. When Jehl worked for Lowrey he was responsible for making multiple copies of a wide range of documents using Edison's electric pen. One of the other duties that came with Jehl's employment with Lowrey was overseeing the care of Bunsen cells which provided the current for the pen. In February 1879 Jehl began his employment with Edison at Menlo Park, a facility in

New Jersey New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware ...

where Edison researched and developed his inventions that had only been around for two years when Jehl arrived. Given his experience at Western Union with Bunsen cells, Jehl maintained 50 or so Bunsen cells on a variety of tables on the second floor of the laboratory. After the completion of Jehl's first assignment, Edison noticed Jehl's work ethic and he was so impressed that he made him a personal assistant. Jehl worked on the

electric lamp An electric light, lamp, or light bulb is an electrical component that produces light. It is the most common form of artificial lighting. Lamps usually have a base made of ceramic, metal, glass, or plastic, which secures the lamp in the soc ...

during the laboratory stage of development. Jehl was responsible for performing many experiments and tests; however, some of the most important were those that were related to the electric meter for the central stations. Edison had given Jehl specific instructions to keep him informed daily with the tests and experiments that he conducted and the results obtained. With the results that Edison received from Jehl, he was able to make informed decisions on how to create things, like the thermal regulator for the meter. The city of

Brno Brno ( , ; german: Brünn ) is a city in the South Moravian Region of the Czech Republic. Located at the confluence of the Svitava and Svratka rivers, Brno has about 380,000 inhabitants, making it the second-largest city in the Czech Republic ...

opted for electric lighting for the

Mahen Theatre Mahen Theatre ( cs, Mahenovo divadlo) is a Czech Republic, Czech theatre situated in the city of Brno. Mahen Theatre, built as German ''Deutsches Stadttheater'' in 1882, was one of the first public buildings in the world lit entirely by electric l ...

in 1882 and contracted the Edison company to supply the lighting system. Jehl supervised the installation. After the

International Electrical Congress The International Electrical Congress was a series of international meetings, from 1881 - 1904, in the then new field of applied electricity. The first meeting was initiated by the French government, including official national representatives, lead ...

in 1881 there was a strong demand for Edison’s products, so Jehl and coworkers conducted Edison’s business in Europe. They promulgated the watt-hour meter and

parallel circuit Terminal (electronics), Two-terminal components and electrical networks can be connected in series or parallel. The resulting electrical network will have two terminals, and itself can participate in a series or parallel Topology (electrical cir ...

distribution grid Electric power distribution is the final stage in the delivery of electric power; it carries electricity from the transmission system to individual consumers. Distribution substations connect to the transmission system and lower the transmissio ...

that Edison had developed with his team including

Francis Upton Francis Robbins Upton (1852 in Peabody, Massachusetts – March 10, 1921 in Orange, New Jersey) was an American physicist and mathematician. Upton worked alongside Thomas Edison in the development of incandescent light bulbs, electric generator ...

. During the two years that Jehl spent at Menlo Park, he kept a personal diary. This diary detailed some of the exceptional things that he personally witnessed during his employment there. This diary was the foundation for Jehl's personal book, titled ''Reminiscences of Menlo Park'', which was published fifty years afterwards. Jehl was one of the

Edison Pioneers The Edison Pioneers was an organization composed of former employees of Thomas Edison who had worked with the inventor in his early years. Membership was limited to people who had worked closely with Edison before 1885. On February 11, 1918, the Ed ...

who gathered in 1918 and thereafter to recall the early collaboration with Edison.

Death

Jehl died on February 11, 1941 in

St. Petersburg, Florida St. Petersburg is a city in Pinellas County, Florida, United States. As of the 2020 census, the population was 258,308, making it the fifth-most populous city in Florida and the second-largest city in the Tampa Bay Area, after Tampa. It is the ...

at the age of 80. Jehl was one of the last surviving associates to Thomas Edison, whom assisted with the creation of the incandescent light. Jehl was survived by his wife, and son Fred Jehl, in

Budapest Budapest (, ; ) is the capital and most populous city of Hungary. It is the ninth-largest city in the European Union by population within city limits and the second-largest city on the Danube river; the city has an estimated population ...

Hungary Hungary ( hu, Magyarország ) is a landlocked country in Central Europe. Spanning of the Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Croatia a ...

Bibliography

* 1899
The Manufacture of Carbons for Electric Lighting and Other Purposes
via

Internet Archive The Internet Archive is an American digital library with the stated mission of "universal access to all knowledge". It provides free public access to collections of digitized materials, including websites, software applications/games, music, ...

* 1937
Menlo Park Reminiscences, volume 1

Edison Institute The Henry Ford (also known as the Henry Ford Museum of American Innovation and Greenfield Village, and as the Edison Institute) is a history museum complex in the Detroit suburb of Dearborn, Michigan, United States. The museum collection contains ...

via

HathiTrust HathiTrust Digital Library is a large-scale collaborative repository of digital content from research libraries including content digitized via Google Books and the Internet Archive digitization initiatives, as well as content digitized locally ...

* 1939
Menlo Park Reminiscences, volume 2
Edison Institute via HathiTrust * 1941
Menlo Park Reminiscences, volume 3
Edison Institute via HathiTrust

References

* "Francis Jehl Dies; An Edison Pioneer" (February 11, 1941),

The New York Times ''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid ...

, page 24 * Israel, Paul (1998) ''Edison: A Life of Invention'',

John Wiley & Sons John Wiley & Sons, Inc., commonly known as Wiley (), is an American multinational publishing company founded in 1807 that focuses on academic publishing and instructional materials. The company produces books, journals, and encyclopedias, in p ...

* Jehl, Francis (July 26, 1936) "Working with Edison", ''The New York Times'' page BR 12 * Josephson, Matthew (1959) ''Edison: A Biography'',

McGraw-Hill McGraw Hill is an American educational publishing company and one of the "big three" educational publishers that publishes educational content, software, and services for pre-K through postgraduate education. The company also publishes referenc ...

* Vanderbilt, Bryon M. (1971) ''Thomas Edison, Chemist'',

American Chemical Society The American Chemical Society (ACS) is a scientific society based in the United States that supports scientific inquiry in the field of chemistry. Founded in 1876 at New York University, the ACS currently has more than 155,000 members at all d ...

{{DEFAULTSORT:Jehl, Francis American inventors 1860 births 1941 deaths Edison Pioneers