Background
Charles William Waidner was born in the suburbs of Baltimore, Maryland, the son of Charles W. Waidner of Baltimore and Sophia (List) Waidner, born in Germany, who was brought to America at the age of one year, her father having left the year previous on account of participation in the Revolution of 1848.
Education
Waidner's education was obtained in the public schools and Friends High School, Baltimore, and at the Johns Hopkins University, where he secured "Proficiency in Electrical Engineering" in 1892 and the degrees of A. B. (1896) and Ph. D. (1898). Here he came under the influence of Prof. Henry A. Rowland and the inspiration of Rowland's immediate associates at a time of exceptional progress in the field of physics. In 1897-98 he held a fellowship, and in the following year an assistantship in physics. In 1899 he was appointed to the faculty of Williams College, Williamstown, Massachussets.
Career
After two academic years at Williams College, Waidner was appointed, August 1, 1901, to the staff of the National Bureau of Standards, newly organized under Samuel Wesley Stratton, becoming the first chief of the Section, later the Division, of Heat and Thermometry. The immediate problem confronting his section was the establishment of a standard scale of temperature, and his work to this end, in collaboration with Dr. George K. Burgess, led eventually to the adoption of the International Temperature Scale. The quality and scope of their studies soon brought the Bureau of Standards recognition as one of the leaders in pyrometric research.
After the temperature scale had been established, attention could be given to problems involving the application of temperature measurements, such as precise calorimetry, the thermodynamic properties of refrigerants, physical constants and properties of materials. During the World War, the division was in charge of work on engines for aviation. All these and other subjects are treated in the publications of the Division of Heat and Thermometry (since 1923 the Division of Heat and Power). During the entire period of his active service to the government, he was a member of the editorial committee which passed on all scientific papers prepared by the staff of the National Bureau of Standards.
To him this meant much more than a perfunctory reading of all papers. It meant a critical study of everyone of them to make sure that the institution which was to such an extent his scientific offspring should not publish any statement or opinion which was open to either doubt or misunderstanding. He was also for sometime chairman of the personnel committee of the Bureau. Completely absorbed in his work, he seldom rested and never took a vacation unless his immediate health required it. He was appointed chief physicist of the Bureau of Standards in 1921 but died early in the following year, leaving no near relatives.
Personality
Waidner's outstanding characteristics were his clear views and accurate thinking on scientific matters, and his devotion to the welfare and progress of those with whom he was associated. The creative thought and sympathetic inspiration of the chief contributed largely to many important pieces of work of his division which do not bear his name, and perhaps his greatest contribution to science is to be found in the work of the men whom he trained and inspired.