Francis Jehl

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Francis Jehl
Born(1860-09-06)September 6, 1860
New York, New York
DiedFebruary 11, 1941(1941-02-11) (aged 80)
St. Petersburg, Florida

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


Before Jehl worked for Edison he worked for Grosvenor P. Lowrey, who was the chief counsel of Western Union Telegraph Company. When Jehl worked for Lowrey he was responsible for making multiple copies of a wide range of documents pertaining to 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 happened to occupy the current of the electric pen. This was particularly important.

In February 1879 Jehl began his employment with Edison at Menlo Park, a facility in New Jersey where Edison researched and developed his inventions that had only been around for two years when Jehl arrived. He was responsible for maintaining 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 gave Jehl a job to work more closely with him. Jehl worked on the electric light 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.

In 1882, Jehl and many of his associates went to Europe in order to participate in the foreign electrical exhibitions. These exhibitions were crucial to the future prospect of international business for the Edison Company. During Jehl's stay in Europe in February 1882, he was supposed to oversee the introduction of the Edison meter. After Jehl helped Edison, he ended up spending forty years in Europe, helping to build power plants and electric lighting systems. Jehl later returned to the United States after World War I, when he supervised the reconstruction of the Menlo Park Laboratory. The reconstruction of the Menlo Park laboratory in Greenfield Village was initiated by Henry Ford.

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 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, Hungary.



  • Francis Jehl Dies; An Edison Pioneer. (New York Times, February 11, 1941), p 24
  • Israel, Paul. Edison: A Life of Invention. (New York, NY: Wiley & Sons, Inc.), 1998
  • Jehl, Francis. Working with Edison. (New York Times, July 26, 1936), p BR 12
  • Josephson, Matthew. Edison: A Biography. (New York, NY: McGraw-Hill), 1959
  • Vanderbilt, Bryon M. Thomas Edison, Chemist. (Washington, D.C.: American Chemical Society), 1971