Bauer, Louis Agricola

(b. Cincinnati, Ohio, 26 January 1865; d. Washington, D.C., 12 April 1932)

geophysics.

Bauer, the founder of the department of terrestrial magnetism of the Carnegie Institution of Washington, was of that line of students of magnetism starting with Halley, and including Gauss and Sabine, who have considered this topic one of the great scientific problems. Originally trained as a civil engineer, he worked from 1887 to 1892 as a computer, primarily on geomagnetism, for the U.S. Coast and Geodetic Survey. From 1892 to 1895 he studied at the University of Berlin and earned the Ph.D. for a thesis on the secular variation of the earth’s magnetism.

On his return from Europe, Bauer taught at the University of Chicago (1895–1896) and the University of Cincinnati (1897–1899). While at the latter he also directed the magnetic work of the Maryland Geological Survey, and from 1899 to 1906 he supervised the expanded geomagnetic work of the Coast and Geodetic Survey. During this period he became convinced that determination of the physical nature of terrestrial magnetism and the explanation of its secular variation required a great increase in observational data. When the Carnegie Institution of Washington was founded in 1902, Bauer proposed a worldwide program of research on the magnetic and electrical condition of the earth and its atmosphere and was appointed head of the new department in 1904.

Undoubtedly the most heroic aspect of Bauer’s work at the Carnegie Institution was the extensive mapping of the earth’s magnetic field on a vast area of the seas, quite like the efforts of Halley and Sabine. Like Gauss and Sabine, he also promoted the establishment of magnetic stations and was active in the mathematical analysis of observations and in the development of a mathematical theory. Bauer paid considerable attention to instrumentation. Although much of his work was devoted to the main magnetic field, he was also interested in atmospheric electricity and extraterrestrial influences on the earth’s magnetism. An example of the latter is his work on the effects of solar eclipses.

Bauer was very active in various international geophysical organizations, such as the International Union of Geodesy and Geophysics. In 1896 he founded the periodical Terrestrial Magnetism (later Terrestrial Magnetism and Atmospheric Electricity), which he edited until 1927. Now known as the Journal of Geophysical Research, the periodical was influential, highly regarded, and played an important role in stimulating geophysical investigations at a time when interest in classical physics was being over-shadowed by newer intellectual pursuits.

Bauer commited suicide at the age of sixty-seven.

BIBLIOGRAPHY

I. Original Works. Bauer has over 300 titles to his credit. While no comprehensive bibliography exists, H. D. Harradon, “Principal Published Papers of Louis A. Bauer,” in Terrestrial Magnetism and Atmospheric Electricity, 37 (Sept, 1932), 220–224, is a good introduction to Bauer’s writings.

Bauer documents are in the Archives of the Carnegie Institution of Washington and the records of the U.S. Coast and Geodetic Survey in the U.S. National Archives, Washington, D.C. The W. F. G. Swann Papers at the American Philosophical Society Library, Philadelphia, and the George Ellery Hale Papers at the Millikan Library, California Institute of Technology, Pasadena, California, contain interesting Bauer correspondence.

II. Secondary Literature. Terrestrial Magnetism and Atmospheric Electricity, 37 (Sept. 1932), 203–420, was the Bauer Memorial Number; it contains a scattering of comments on Bauer, as well as many articles showing the state of development of fields he worked in. Both the Annual Report of the U. S. Coast and Geodetic Survey and the Yearbook of the Carnegie Institution of Washington for the years when Bauer was with them are replete with information on his career. The best general secondary source on Bauer’s principal intellectual interest is Sydney Chapman and Julius Bartels, Geomagnetism, 2 vols. (Oxford, 1940), which has many specific references to Bauer. An additional virtue of the work is that the authors have, implicitly and explicitly, attempted to place recent works in a historical perspective.

Nathan Reingold