Louis Winslow Austin


Louis Winslow Austin was an American physicist known for his research on long-range radio transmissions.
Austin was born in Orwell, Vermont, and educated at Middlebury College and the University of Strasbourg, from which he received a Ph.D. in 1893. From 1893-1901, he taught physics as an instructor and assistant professor at the University of Wisconsin–Madison, then returned to Germany for two years at the Physikalisch-Technische Reichsanstalt in Berlin where he performed research on hot gases.
In 1904 Austin joined the National Bureau of Standards to study radio propagation. After the United States Navy established its Naval Radio Telegraphic Laboratory within the bureau, Austin served as its director from 1908–1923, and from 1923-1932 as chief of the Radio Physics Laboratory.
Austin's research focused on radio propagation and static, and more specifically the influence of temperature, humidity, magnetic storms, and sunspots on long-range radio transmissions. Under his direction, the Navy conducted long-distance wireless measurements in 1909 and 1910 between the USS Birmingham and USS Salem, as they steamed to Liberia and back, and Fessenden's station at Brant Rock, Massachusetts. Austin measured received impulses from the ships on the 3,750 and 1,000 meter wavelengths to determine the relationships between radio frequency, distance, and received signal strength. These measurements led Austin and collaborator Dr. Louis Cohen to develop the empirical Austin-Cohen formula for predicting radio signal strength at long distances.
Austin joined the Institute for Radio Engineers in 1913, in 1914 served as its third president, and in 1927 received its Medal of Honor "for his pioneer work in the quantitative measurement and correlation of factors involved in radio wave transmission." He also served as a U.S. representative at numerous international radio conferences. Austin died on June 27, 1932, in Washington, D.C.

Personal life

Louis Winslow Austin was born 30 October 1867 at Orwell, Addison Co., Vermont, USA. He was the only child of Lewis Augustine Austin and Mary Louise Austin née Taft. As a child, he lived with his parents at Manchester, Bennington Co., Vermont, USA 1868-1872 and Meriden, Sullivan Co., New Hampshire, USA 1872-1880. He lived at Middleburg, Vermont from 1880-1889. Strassburg, Germany 1889-1893. Madison, WI, 1893-1901, where he concluded as Assistant Professor of Physics at the University of Wisconsin. He married Laura Osborne on 16 August 1898 at La Crosse, La Crosse County, Wisconsin.
Laura Alma Austin née Osborne was born 10 August 1875 at McGregor, Clayton Co., Iowa. She was the second of three children to Willis Leroy Osborne and Julia Livia Osborne née Colman. She lived with her parents at McGregor, Iowa 1875-1877 and La Crosse, Wisconsin 1877-1898 until her marriage. She was a student at the University of Wisconsin, graduating in the class of 1897 with a degree of Arts Bachelor. She was a member of Kappa Alpha Theta fraternity. Laura remained actively involved with her alma mater throughout her life. She was a life member of the Alumni Association of the University of Wisconsin and served several roles within the organisation. She frequently accompanied her husband in his travels. There were no children to the marriage.

Professional life

Brief chronology

Austin commenced his studies at Middlebury College, circa 1887 and graduated as Bachelor of Arts in 1889.

University of Strassburg, Strassburg, Germany: 1889-1890

Clark University, Worcester, Worcester Co., Massachusetts, US: 1890-1891

Austin served one year as Fellow in Physics at Clark University in Massachusetts, then returned to Germany to complete his doctoral studies.

University of Strassburg, Strassburg, Germany: 1891-1893

University of Wisconsin, Madison, Dane Co., Wisconsin, USA: 1893-1897

Austin commenced with the University of Wisconsin as an Instructor in Physics in 1893, soon after the award of his Ph.D. In 1895 he was promoted to the position of Assistant Professor of Physics. At the time, the President of the University was Charles Kendall Adams and the Vice President was John Barber Parkinson. Physics then came within the College of Letters and Science under Dean Edward Asahel Birge. Other faculty members in the field of Physics at the time were Benjamin Warner Snow, John Eugene Davies, Charles Burton Thwing and Ervin Sidney Ferry.
Laboratory practice was a significant part of Austin's curriculum and in this he greatly emphasised the need for careful attention to detail to achieve the highest possible accuracy with the instruments available. This approach was heavily influenced by his time in Germany and served him well throughout his later career.
He was a close associate of Thwing, who had also received a Ph.D. in Germany. In their approaches to laboratory practice, Thwing and Austin were closely similar. Finding little introductory laboratory material available, together they authored in 1895 a useful book "Exercises in Physical Measurement" for first year laboratory students. It was published the following year and immediately found application both in the classes of the University and more widely. Within its pages one can see evidence of future techniques which would place him at the forefront of the radio pioneering empiricists.

Physikalisch-Technische Reichsanstalt, Charlottenburg, Germany: 1901-1902

Returning to Germany in 1901, Austin worked at the renowned Physikalisch-Technische Reichsanstalt now Physikalisch-Technische Bundesanstalt in Charlottenburg. There he studied the properties of gases at high temperatures. Together with colleague Starke, he is credited with the discovery of secondary electron emission in 1902, which they reported in an article in Annalen der Physik. But the discovery had to await almost two decades for commercial applications to develop in the form of the photomultiplier, a key enabler of television technology and today's advances in neutrino detectors. The primary function of the Physikalisch-Technische Reichsanstalt in Germany was to establish national metrological standards including measurement and calibration techniques. In the USA that function was charged to the Bureau of Standards and Austin's work at the PTR would have been favourably viewed by his future employer.

University of Wisconsin, Wisconsin, USA: 1902-1904

Austin resumed his position of Assistant Professor of Physics the University of Wisconsin in 1902 and continued there until 1904.

Bureau of Standards, Washington, District of Columbia, USA: 1904-1908

Naval Radio-Telegraphic Research Laboratory, Bureau of Standards, Washington, District of Columbia, USA: 1908-1923

Bureau of Standards, Washington, District of Columbia, US: 1923-1932

Austin-Cohen Formula

A mathematical model for propagation of radio frequency electromagnetic waves along the surface of the earth was for some decades one of the greatest mathematical challenges, engaging the minds of some of our foremost mathematicians. Throughout that period, as each new model was developed and promoted, it had to withstand the immediate question "how well does it match the Austin-Cohen formula?" This was the lasting testament of a few years circa 1911 of exacting measurements undertaken by Austin and his friend and colleague Louis Cohen. As in so many scientific accomplishments, there were elements of serendipity to the experiments. As is now well known the independent variables are frequency/wavelength, distance, surface conductivity. The latter variable is particularly troublesome varying greatly with the type of the ground, its depth profile, cover and moisture content; almost impossible to measure directly. A further complication is that the type of ground will itself vary over large distances of the order of 100s of kilometres. Today effective ground conductivity is mostly calculated from measurement of the actual attenuation of radio waves propagating over that surface. But Austin's then employer was the US Department of Navy and they were principally interested in communications shore to ship and ship to ship. Austin's measurements were almost entirely over sea which has the admirable quantity of both homogeneity and constancy of surface conductivity. By eliminating conductivity from the variable set, Austin meticulous measurements with carefully calibrated but rudimentary instruments of the day, produced a clean set of data of field strength against frequency and distance. The resulting empirical model was simple, elegant and precise. It would provide for decades both his employers with a scientific basis to plan their naval radio communications services as well as the brightest mathematicians a yardstick against which to test their surfacewave propagation deterministic models. Had Austin extended his data to include the land of highly variable surface conductivity to the north, west and south of the transmitters available to him, the resultant data would have been almost chaotic for the day and likely necessitated a stochastic model for solution, similar to the problem of night-time skywave propagation to which he devoted much of his time in his remaining two decades.

Biographies

Miscellaneous