ROBERTS-AUSTEN, WILLIAM CHANDLER

(b. Kennington, Surrey, England, 3 March 1843; d. London, England, 22 November 1902) metallurgy.

Roberts-Austen was the eldest son of George Roberts and Maria Louisa Chandler. (In 1885, as heir of his uncle Nathaniel Lawrence Austen and at his request, he adopted by royal license the additional surname Austen. His early work is published under the name Roberts.) After private education he entered the Royal School of Mines, South Kensington, London, at the age of eighteen, becoming an associate in 1865. Although he intended to be a mining engineer, his career was determined by his becoming private assistant to Thomas Graham, then master of the mint. Roberts is said to have done some of Graham’s experimental work on colloids; and although he was not officially connected with the mint it was in its work that he became most adept. After Graham’s death in 1869, the Treasury gave him an official post as part of a long-planned reorganization, placing him in charge of the assay of coin (bullion was assayed by another officer). In 1882 the two posts were combined and Roberts-Austen became “chemist and assayer of the mint,” a position he occupied until his death.

In 1870, with the deputy-master of the mint, Sir Charles Fremantle, Roberts-Austen toured thirteen European mints to study their methods, a journey that marked the beginning of his international interests and influence. He conferred with Jean Stas, who was head of the Brussels mint, and as a result introduced into the British mint the volumetric, argentometric assay devised by Gay-Lussac for the Paris mint in 1832. Official confidence in him was shown by his being entrusted with the preparation in 1873 of trial plates (the legal standards of reference at the annual “trial of the pyx,” for checking gold and silver coinage).

Roberts-Austen’s study of the means of preparing plates of fine gold and silver led him to a fundamental study of the constitution of alloys, into which he introduced new physicochemical theories and new experimental techniques. He applied calorimetric methods to the measurement of the solidification of copper-silver alloys, expressing his results for the first time as “freezing-point” curves.

In 1876, in conjunction with Joseph Lockyer, Roberts-Austen studied the possibility of using the spectroscope for quantitative analysis. Although the method was not adopted at the mint, his interest stimulated its progress. This is characteristic of the way in which research aimed at supplementing the traditional methods of assay yielded scientific results of wider significance. He was elected a fellow of the Royal Society in 1875 and was an original member of the Physical Society at its formation in 1874.

In 1880 John Percy resigned his post of professor of metallurgy at the Royal School of Mines, following his disagreement with a proposal to move the whole school to South Kensington. Roberts-Austen was appointed to succeed him while still retaining his post at the mint. The report of the deputy master of the mint stated: “This Department could not fail to derive advantage from the appointment of the Chemist of the Mint to a position in which, as Professor, every advance in metallurgical science must of necessity come under his notice.” A worthy successor to Percy, Roberts-Austen was an excellent teacher and enlarged the scope of research at the school.

In 1880 Roberts-Austen began a long study of the hardening of steel, important to the mint because of the use of steel for dies. The mint’s needs were soon met; but the fundamental study continued, particularly under the encouragement given by the Institution of Mechanical Engineers. It led to the important series of Alloys Research Reports.

For the rest of his career Roberts-Austen succeeded in maintaining the difficult balance between the administrative demands of a post and the effective pursuit of the scientific inquiries it generates. In 1883 he toured the principal mints and assay offices in the United States, and in 1885 he began a study of the effect of small amounts of impurity on the tensile strength of standard gold. This work was developed in the next few years and was considered in a paper of 1888 that was an early example of the interpretation of the properties of a range of elements in terms of the periodic classification of the elements.

Roberts-Austen’s work had been so successful up to this time that he might well have been content to continue to use the same methods. In 1890, however, he not only adopted methods and attitudes that were very advanced for the time but also initiated new ones. Experimentally he recognized the inadequacy of the calorimetric methods he had used for the study of fused alloys, and adopted Le Chatelier’s thermocouple pyrometer. He added greatly to the utility of the mirror galvanometer that detected the thermocouple response by recording the movements of the reflected beam photographically. The ability to record rates of cooling in masses of high melting point extended Roberts-Austen’s knowledge of eutectics and gave him the basis of a theory of alloy composition. In 1891 he described an alloy of gold and aluminum that he recognized as the first true intermetallic compound. His automatic recording pyrometer later proved of great industrial use.

Roberts-Austen also developed the use of photomicrography in the study of metal crystal structures, his apparatus providing the pattern for similar installations in industry, the Royal Arsenal, and the engineering laboratory at Cambridge. He served on many committees, the most important of which was that leading to the establishment of the National Physical Laboratory. He was honored as a K.C.B. in 1899.

Roberts-Austen studied historical metallurgy, investigating with the sculptor Alfred Gilbert the revival of fifteenth-century methods of casting. He lectured widely on the colors of metals for artwork and even referred to the subject in official mint reports. His principal publication, the textbook Introduction to the Study of Metallurgy (1891), ran to six editions and was very influential.

BIBLIOGRAPHY

I. Original Works. Roberts-Austen’s largest single work was Introduction to the Study of Metallurgy (London, 1891, 1893, 1894, 1897, 1902, 1908). Over 80 papers dealing with metallurgical subjects are listed in Smith (see below), together with 12 written in collaboration on related subjects, such as spectroscopic analysis. Eight papers deal with the metallurgy of art objects.

II. Secondary Literature. Roberts-Austen’s most important and characteristic papers were assembled by his colleague S. W. Smith in Roberts-Austen: A Record of His Work (London, 1914). They are presented in groups and interspersed with biographical matter, his several parallel careers being given separate chronological treatment. More orthodox summary accounts of his life are given in London Times (24 Nov. 1902), 9; Engineering, 74 (1902), 717–718, with portrait; Journal of the Iron and Steel Institute, 62 (1902), 361–364; and Proceedings of the Royal Society, 75 (1905), 192–198.

Frank Greenaway