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 inventi ...

. Jehl studied chemistry at Cooper Union 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 Thomas Edison's electric pen, part of a complete outfit for duplicating handwritten documents and drawings, was the first relatively safe electric-motor-driven office appliance produced and sold in the United States. Development Edison recogniz ...

. One of the other duties that came with Jehl's employment with Lowrey was overseeing the care of

Bunsen cell The Bunsen cell is a zinc-carbon primary cell (colloquially called a "battery") composed of a zinc anode in dilute sulfuric acid separated by a porous pot from a carbon cathode in nitric or chromic acid. Cell details The Bunsen cell is abou ...

s which provided the

current Currents, Current or The Current may refer to: Science and technology * Current (fluid), the flow of a liquid or a gas ** Air current, a flow of air ** Ocean current, a current in the ocean *** Rip current, a kind of water current ** Current (stre ...

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 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 opted for electric lighting for the

Mahen Theatre Mahen Theatre ( cs, Mahenovo divadlo) is a 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 light. Ort (200 ...

in 1882 and contracted the Edison company to supply the lighting system. Jehl supervised the installation. After the International Electrical Congress 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 North American domestic analog electricity meter. Electricity meter with transparent plastic case (Israel) North American domestic electronic electricity meter An electricity meter, electric meter, electrical meter, energy meter, or kilowa ...

and

parallel circuit 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. Whether a two-terminal "object" is a ...

distribution grid that Edison had developed with his team including Francis Upton. During the two years that Jehl spent at Menlo Park, he kept a personal

diary A diary is a written or audiovisual record with discrete entries arranged by date reporting on what has happened over the course of a day or other period. Diaries have traditionally been handwritten but are now also often digital. A personal ...

. 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 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 Pannonian Basin, Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the ...

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 * 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 d ...

, 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, ...

* 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 refere ...

* 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 ...

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