Edward Bennett Rosa
Biography of Edward Bennett Rosa
Edward Bennett Rosa was the son of Reverend Edward David and Sarah Gilmore (Roland) Rosa; the grandson of Cornelius and Mary (Doty) Rosa; and a descendant of Albert Heymans Roosa, who
emigrated from Holland in 1660 and settled with his wife and family of eight children on the Hudson River, near Newburgh, N. Y.
He received his college education at Wesleyan University, Middletown, Connecticut, from which he was graduated at the head of his class, receiving the degree of B. S. in 1886.
He subsequently taught physics and chemistry in the English and Classical School in Providence, Rhode Island, where he remained two years. He then entered Johns Hopkins University as a graduate student in and received the degree of Doctor of Philosophy in 1891. In 1906, in recognition of his contributions to science, the honorary degree of Doctor of Science was conferred upon him by Wesleyan University.
During the first part of the year 1890 Dr. Rosa was assistant professor of physics at the University of Wisconsin, leaving there to become associate professor of physics at Wesleyan University, Middletown, Connecticut in 1891, and professor of physics in 1892. He retained the professorship of physics (the Charlotte Augusta Ayers' professorship) for ten years, when, in 1901, he was called to the newly-organized National Bureau of Standards, at Washington. There, as physicist, and later on, as chief physicist, he continued through the remainder of his life. His was a short span of three score years—one score of which was spent at the National Bureau of Standards.
Dr. Rosa's research work began at Wesleyan University, where in association with Professor Wilbur Olin Atwater (1844-1907), he developed the physical side of the respiration calorimeter, known
under the joint name Atwater-Rosa respiration calorimeter. The practical details of the construction of the instrument were chiefly Dr. Rosa's. This apparatus was of great value in the pioneer investigations of the value of foods, and in the study of problems in nutrition.
While at Wesleyan University he invented and developed a curve tracer (the Rosa curve tracer) for delineating the form of alternating electric currents, a problem of interest in the operation of alternating current machinery. The original curve tracer is still to be seen in the physical laboratory of Wesleyan University.
Probably the most important epoch in Dr. Rosa's scientific life began in 1901 when he undertook work at the National Bureau of Standards, under the directorship of Samuel Wesley Stratton (1861-1931). In those days, the second in command was Dr. Rosa, ranking physicist and chief of the electrical division, where from the start he proved his abilities as an efficient administrator.
When Dr. Rosa began his work in the Electrical Division of the National Bureau of Standards it was his ambition to determine a number of the fundamental electrical constants to a degree of accuracy far exceeding all previous determinations. To partly attain this goal he was singularly fortunate in having as a co-worker, Dr. N. E. Dorsey.
One of these determinations was the ratio of the electromagnetic and the electrostatic units. This work was started early in 1907 in conjunction with Dr. Dorsey, through whose skillful and painstaking experimental technique there resulted the most accurate determination yet made of this constant.
About 1907 Dr. Rosa with Dr. Dorsey started their determination of the absolute value of the ampere. This work extended over a period of years, and gave a more reliable value of the ampere than any previously obtained. In order to obtain a concrete representation of the ampere, Dr. Rosa with the assistance of Dr. G. W. Vinal carried on an investigation of the silver voltameter simultaneously with the absolute determination of the ampere, and it is largely as a result of this work that
we are now able to define the ampere in a satisfactory manner.
In 1910 under Dr. Rosa's direction an exhaustive investigation was instituted into the subject of electrolytic corrosion of underground gas and water pipes, and lead cable sheaths, due
to stray currents from electric railways.
During World War I Rosa directed the development of a number of scientific instruments which were of great value to the American Forces in France. Among these were a sound ranging device for locating big guns ; the geophone for the detection of mining operations; the development of aircraft radio apparatus; and the improvement of radio direction finders by which enemy ships and air craft could be located.
Under his direction at the National Bureau of Standards was established perhaps the finest radio research laboratory in the country, and he always showed an intense interest in improving
apparatus and methods of radio communication. In addition to his diversified work in the field of electrical research, Dr. Rosa was keenly interested in the prevention of industrial accidents and in the promulgation of safety standards for use by state, municipal and insurance organizations. He conceived the idea of a National Electrical Safety Code.
Edward Bennett Rosa, chief physicist, died suddenly while engaged in work in his office at the National Bureau of Standards at Washington, D. C, in the afternoon of May 17, 1921.
He was married to Mary Evans, daughter of William W. Evans of Harrisburg, Pennsylvania, on March 22, 1894. There were no children.
- Samuel Wesley Stratton:
Edward Bennett Rosa. Science, June 24, 1921, 53 (1382): 569.
- William Weber Coblentz (1873-1962):
Biographical memoir of Edward Bennet Rosa, 1861-1921.
National Academy of Sciences of the United States of America. Biographical memoirs, volume 16, eight memoir. Presented to the Academy at the autumn meeting, 1934.