Kennelly
NAME:
Kennelly, Arthur Edwin
ACHIEVEMENTS:
Co-disovered the ionosphere
NICKNAME/ALIAS:
None
DATE AND PLACE OF BIRTH:
17 December 1861, Colaba, nr Bombay, India
DATE AND PLACE OF DEATH AND AGE AT DEATH:
18 June 1939, Boston, MA. Aged 78
DISCIPLINE:
Electrical engineer
FIELD:
Electronics
LANGUAGE:
English
PARENTS:
Father: David Joseph Kennelly
Mother: Katharine Heycock
SIBLINGS:
1 sister
many step-siblings
SPOUSE:
Julia Grice
CHILDREN:
1 son: Reginald Grice Kennelly
EDUCATION:
Private schools on the continent and in Britain
University College School, London
MAJOR WORK:
"Impedance" (1893, in "Transactions of the American Institute of Electrical
Engineers, vol. X)
LIFE AND TIMES:
When he was twelve Kennelly heard a lecture on submarine telegraphy which aroused his interest in electricity. He left school the next year and worked as an office boy at the Society of Telegraph Engineers, studying electrophysics in his spare time. When he was fifteen he got a job as telegraph operator in the Eastern Telegraph Company (which operated the submarine telegraph system linking England to the continent and the East). In 1887 he emigrated to the United States to join <worked for> Edison's* electrical laboratory at New Orange, New Jersey.
He made his first important contribution to circuit theory when he rationalized the mathematical analysis for alternating currents. His findings, published in 1893 as: "Impedance" in "Transactions of the American Institute of Electrical Engineers" allowed electrical engineers to use complex numbers in the analysis of alternating-current problems.
The following year he expanded the work of the English physicist <expanded work of> Heaviside* in this area and provided tables and charts.
Kennelly left the Edison laboratories in 1894, and set up his own firm of consulting engineers. Kennelly had made his mark within his profession and in 1898-1900 he served
as president of the American Institute of Electrical Engineers.
He continued to specialize in laying submarine cables and in 1902 directed the laying of a submarine cable from Vera Cruz to Campeche for the Mexican government. In the same year, he became professor of engineering at Harvard University.
When <work related to> Marconi* achieved transmission of transatlantic radio waves in 1901, Kennelly had observed that their reception in Novia Scotia was much better than that forecast by contemporary radio wave theory. In March 1902 he suggested that this was because the radio waves were bounced back to earth from an ionized layer in the upper atmosphere.
Heaviside independently came up with the same theory shortly afterwards and the ionized layer is now known as the Kennelly-Heaviside layer and experimentally verified by <discovery verified by> Appleton* in 1924 with the discovery of the <predicted>Appleton layer*.
In 1908 he and G W Pierce produced a mathematical analysis for evaluating the performance of telephone receivers. Kennelly was a gifted teacher and from 1913, in addition to his work at Harvard, he taught at the Massachusetts Institute of Technology, where he also directed research in electrical engineering.
ASSESSMENT: Kennelly is best-known for his contribution to radio wave theory.
EXTRA CONNECTIONS: None
ONELINER: AF Kennelly, co-discoverer of the ionosphere
BIBLIOGRAPHY:
Dictionary of American Biography
Dictionary of Scientific Biography
Encylopedia Britannica