Arthur Edwin Kennelly (December 17, 1861 – June 18, 1939) was an American electrical engineer.

Biography

Kennelly was born December 17, 1861, in Colaba, in Bombay Presidency,

British India The provinces of India, earlier presidencies of British India and still earlier, presidency towns, were the administrative divisions of British governance on the Indian subcontinent. Collectively, they have been called British India. In one ...

, and was educated at

University College School ("Slowly but surely") , established = , closed = , type = Public schoolIndependent day school , religion = , president = , head_label = Headmaster , head = Mark Beard , r_head_label = , r_he ...

in London. He was the son of Irish naval officer Captain David Joseph Kennelly (1831–1907) and Catherine Gibson Heycock (1839–1863). His mother died when he was three years old. In 1863, his father retired from the navy and later Arthur and his father returned to England. In 1878, his father married Ellen L.Spencer and moved the family to Sydney, Nova Scotia, when he took over the Sydney and Louisbourg Coal and Railway Company Limited. By his father's third marriage, Arthur gained four half siblings, Zaida Kennelly in 1881, David J. Kennelly Jr. in 1882, Nell K. Kennelly in 1883, and Spencer M. Kennelly in 1885. Kennelly joined

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 ...

's West Orange laboratory in December 1887, staying until March 1894. While there he had a role in the

war of currents The war of the currents was a series of events surrounding the introduction of competing electric power transmission systems in the late 1880s and early 1890s. It grew out of two lighting systems developed in the late 1870s and early 1880s; arc ...

, assisting anti-

alternating current Alternating current (AC) is an electric current which periodically reverses direction and changes its magnitude continuously with time in contrast to direct current (DC) which flows only in one direction. Alternating current is the form in whic ...

crusader Harold P. Brown in developing a demonstration to show how alternating current was more dangerous than

direct current Direct current (DC) is one-directional flow of electric charge. An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor such as a wire, but can also flow through semiconductors, insulators, or eve ...

as well as a further test to determine the type of electricity that should be used in the

electric chair An electric chair is a device used to execute an individual by electrocution. When used, the condemned person is strapped to a specially built wooden chair and electrocuted through electrodes fastened on the head and leg. This execution method, ...

, convincing officials that it should be alternating current. Kennelly then formed a consulting firm in electrical engineering with Edwin Houston. Together they wrote ''Alternating Electric Currents'' (1895), ''Electrical Engineering leaflets'' (1896), and ''Electric arc lighting'' (1902). In 1893, during his research in electrical engineering, he presented a paper on " Impedance" to the

American Institute of Electrical Engineers The American Institute of Electrical Engineers (AIEE) was a United States-based organization of electrical engineers that existed from 1884 through 1962. On January 1, 1963, it merged with the Institute of Radio Engineers (IRE) to form the Insti ...

(AIEE). He researched the use of

complex number In mathematics, a complex number is an element of a number system that extends the real numbers with a specific element denoted , called the imaginary unit and satisfying the equation i^= -1; every complex number can be expressed in the fo ...

s as applied to Ohm's Law in

circuit theory Circuit may refer to: Science and technology Electrical engineering * Electrical circuit, a complete electrical network with a closed-loop giving a return path for current ** Analog circuit, uses continuous signal levels ** Balanced circui ...

. In 1902, he investigated the ionosphere's radio spectrum's electrical properties, resulting in the concept of the Kennelly–Heaviside layer. Also in 1902 Kennelly was given the entire engineering charge of the expedition which laid Mexican submarine cables on the route Vera Cruz–Frontera–Campeche. He also served as inspector for the Mexican Government during the manufacture of the cable. He was a professor of electrical engineering at

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of high ...

, 1902–1930, and jointly at the

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...

, 1913–1924. One of his PhD students was

Vannevar Bush Vannevar Bush ( ; March 11, 1890 – June 28, 1974) was an American engineer, inventor and science administrator, who during World War II headed the U.S. Office of Scientific Research and Development (OSRD), through which almost all warti ...

. In 1911 and 1912, Kennelly advanced applied mathematics by communicating the theory of the

hyperbolic angle In geometry, hyperbolic angle is a real number determined by the area of the corresponding hyperbolic sector of ''xy'' = 1 in Quadrant I of the Cartesian plane. The hyperbolic angle parametrises the unit hyperbola, which has hyperbolic function ...

and

hyperbolic functions In mathematics, hyperbolic functions are analogues of the ordinary trigonometric functions, but defined using the hyperbola rather than the circle. Just as the points form a circle with a unit radius, the points form the right half of the un ...

, first in a course at the

University of London The University of London (UoL; abbreviated as Lond or more rarely Londin in post-nominals) is a federal public research university located in London, England, United Kingdom. The university was established by royal charter in 1836 as a degree ...

and then in a published book. He was an active participant in professional organizations such as the Society for the Promotion of the Metric System of Weights and Measures, the Illuminating Engineering Society and the US National Committee of the International Electrotechnical Commission, and also served as the president of both the AIEE and the Institute of Radio Engineers, IRE, during 1898–1900 and 1916, respectively. He was an Invited Speaker of the ICM in 1924 at Toronto. While Kennelly himself does not appear to have been a significant athlete, he applied his engineering expertise to his avocation: analyzing endurance sports records of horses and humans. He noticed that time vs. distance plots of such sports records formed nearly a straight line when plotted on log-log graph paper. Kennelly thus preceded by 75 years Peter Riegel, who also—apparently independently—noticed this same power law, called by Riegel the "endurance equation". Due to the relatively crude (by today's standards) data available, Kennelly's "Law of Fatigue" utilized the same exponent 9/8 = 1.125 for all of his datasets, whereas Riegel noticed that these exponents differed by sport and by individual. Kennelly died in Boston, Massachusetts, on June 18, 1939.

Awards and honors

Kennelly received awards from many nations, including the IEE Institution Premium (1887), the

Edward Longstreth Medal The Franklin Institute is a science museum and the center of science education and research in Philadelphia, Pennsylvania. It is named after the American scientist and statesman Benjamin Franklin. It houses the Benjamin Franklin National Memori ...

(1917) and the Howard N. Potts Medal (1918) of the

Franklin Institute The Franklin Institute is a science museum and the center of science education and research in Philadelphia, Pennsylvania. It is named after the American scientist and statesman Benjamin Franklin. It houses the Benjamin Franklin National Memori ...

, the Cross of a Chevalier of the Légion d'honneur of France and the

AIEE Edison Medal The IEEE Edison Medal is presented by the Institute of Electrical and Electronics Engineers (IEEE) "for a career of meritorious achievement in electrical science, electrical engineering, or the electrical arts." It is the oldest medal in this fi ...

(1933), now IEEE Edison Medal, "For meritorious achievements in electrical science, electrical engineering and the electrical arts as exemplified by his contributions to the theory of electrical transmission and to the development of international electrical standards." He was awarded the

IRE Medal of Honor The IEEE Medal of Honor is the highest recognition of the Institute of Electrical and Electronics Engineers (IEEE). It has been awarded since 1917, when its first recipient was Major Edwin H. Armstrong. It is given for an exceptional contributio ...

(1932), now IEEE Medal of Honor, "For his studies of radio propagation phenomena and his contributions to the theory and measurement methods in the alternating current circuit field which now have extensive radio application."

Works

* See Edwin Houston for the works co-authored with him.

Books

* with Henry David Wilkinson
Practical notes for electrical students
(London: "The Electrician" Prtg. & Pub. Co., 1890)
Wireless telegraphy and wireless telephony an elementary treatise
(New York: Moffat, Yard & Co., 1913)
The application of hyperbolic functions to electrical engineering problems; being the subject of a course of lectures delivered before the University of London in May and June 1911
(London: University of London Press, 1912)
Artificial Electric Lines: Their Theory, Mode of Construction and Uses
(New York: McGraw-Hill, 1917) * Vestiges of Pre-metric Weights and Measures Persisting in Metric-system Europe 1926-1927 (New York: The Macmillan Company. 1928) * Electricity in Electro-Therapeutics (The W.J. Johnson Company 1896)

Patents

* — "Electric meter" * — "Electrostatic voltmeter"

References

External links

* * Katz, Eugenii, . Biographies of Famous Electrochemists and Physicists Contributed to Understanding of Electricity, Biosensors & Bioelectronics.
Photo of Arthur E. Kennelly

* ttp://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/kennelly-arthur.pdf National Academy of Sciences Biographical Memoir {{DEFAULTSORT:Kennelly, Arthur Edwin 1861 births 1939 deaths American electrical engineers Harvard University faculty Irish emigrants to the United States IEEE Medal of Honor recipients Edison Pioneers People educated at University College School IEEE Edison Medal recipients Howard N. Potts Medal recipients