Radio pioneer Arthur Edwin Kennelly, the son of an Irish naval officer, was born in Colaba, India (near Bombay), on 17 December 1861. Educated in England and France, he left school at the age of thirteen and taught himself physics while working as a telegrapher. In 1876, he left England and held various positions, including that of an assistant electrician in Malta, chief electrician of a cable repairing steamer, and, finally, senior ship’s electrician. In 1887, he immigrated to the United States and became principal assistant in Thomas Edison’s West Orange, New Jersey lab. Between 1894 and 1901, Kennelly worked as a consulting engineer for the Edison General Electric Company of New York. He then formed the consulting firm of Houston and Kennelly in Philadelphia with Edwin J. Houston. In 1902, the government of Mexico retained his firm to oversee the laying of the Veracruz-Frontera-Campeche cables. Kennelly also had a career in academia—he was a Professor of Electrical Engineering both at Harvard University and the Massachusetts Institute of Technology (MIT) and was a research associate at the Carnegie-Mellon Institute.
In 1901, Kennelly noticed that Guglielmo Marconi’s reception in Newfoundland of radio signals transmitted from England was received far better than predicted by radio-wave theory. Kennelly and the Englishman Oliver Heaviside, independently, and at approximately the same time in 1902, announced the probable existence of a layer of ionized gas high in the atmosphere that reflected radio waves. Formerly called the Heaviside or Kennelly-Heaviside layer (now called the E region), it is one of the several layers of the ionosphere. Although short wavelength radio waves penetrate the ionosphere, longer waves reflect off it instead, a property which allows them to “curve” around the earth and be propagate far beyond the horizon. Kennelly is also known for the contributions he made to the analysis of alternating-current (AC) circuits with the publication of his paper “Impedance.” In that paper he described the first use of complex numbers as applied to Ohm’s Law in AC circuit theory.
Kennelly received many awards during his lifetime. These included the IEE Institution Premium, the Franklin Institute Howard Potts Gold Medal, the Cross of a Chevalier of the Legion d’Honneur of France, and the AIEE Edison Medal (1933). In 1932 he received the IRE Medal of Honor “[f]or 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.” He served as president of the American Institute of Electrical Engineers fron 1898 to 1900 and president of the Institute of Radio Engineers in 1916. Kennelly died in Boston, Massachusetts on 18 June 1939.
Vannevar Bush was an American engineer, inventor and science administrator, whose most important contribution was as head of the U.S. Office of Scientific Research and Development (OSRD) during World War II, through which almost all wartime military R&D was carried out, including initiation and early administration of the Manhattan Project. His office was considered one of the key factors in winning the war. He is also known in engineering for his work on analog computers, for founding Raytheon, and for the memex, an adjustable microfilm viewer with a structure analogous to that of the World Wide Web. In 1945, Bush published As We May Think in which he predicted that “wholly new forms of encyclopedias will appear, ready made with a mesh of associative trails running through them, ready to be dropped into the memex and there amplified”. The memex influenced generations of computer scientists, who drew inspiration from its vision of the future.
For his master’s thesis, Bush invented and patented a “profile tracer”, a mapping device for assisting surveyors. It was the first of a string of inventions. He joined the Department of Electrical Engineering at MIT in 1919, and founded the company now known as Raytheon in 1922. Starting in 1927, Bush constructed a differential analyzer, an analog computer with some digital components that could solve differential equations with as many as 18 independent variables. An offshoot of the work at MIT by Bush and others was the beginning of digital circuit design theory. Bush became Vice President of MIT and Dean of the MIT School of Engineering in 1932, and president of the Carnegie Institution of Washington in 1938.
Bush was appointed to the National Advisory Committee for Aeronautics (NACA) in 1938, and soon became its chairman. As Chairman of the National Defense Research Committee (NDRC), and later Director of the Office of Scientific Research and Development (OSRD), Bush coordinated the activities of some six thousand leading American scientists in the application of science to warfare. Bush was a well-known policymaker and public intellectual during World War II, when he was in effect the first presidential science advisor. As head of NDRC and OSRD, he initiated the Manhattan Project, and ensured that it received top priority from the highest levels of government. In Science, The Endless Frontier, his 1945 report to the President of the United States, Bush called for an expansion of government support for science, and he pressed for the creation of the National Science Foundation.