by P. A. Sheppard, rev. Isobel Falconer
© Oxford University Press 2004 All rights reserved
Walker, Sir Gilbert Thomas (1868-1958), applied mathematician and meteorologist, was born in Rochdale, Lancashire, on 14 June 1868, the fourth child in a family of eight of Thomas H. Walker, civil engineer, and his wife, Charlotte (or Elizabeth) Haslehurst. His father moved to Croydon and became borough engineer. Walker was educated first at Whitgift Grammar School (1876-1881) and then at St Paul's School (to 1886), from which he gained a mathematical scholarship to Trinity College, Cambridge. He was senior wrangler in part one of the mathematical tripos in 1889 and again in part two in 1890, and was elected a fellow of Trinity in 1891. In 1890 his health broke down and he had to spend the following three winters in Switzerland, where he became interested in skating. On his recovery he became lecturer in mathematics at Trinity in 1895.
From 1892 onwards Walker published a series of papers on electromagnetism for one of which, 'Aberration and some other problems connected with the electro-magnetic field', he was awarded an Adams prize in 1899. This interest appears to have come to a close with the publication of his lectures on the Theory of Electromagnetism in 1910. An equally early but more sustained interest was in the physics of projectiles, ball games, and flight. Here his work was both practical and theoretical, for he became expert in the design and use of primitive projectiles, such as the boomerang and stone-age celt--he was known to his early Cambridge friends as Boomerang Walker--and he contributed a fine article entitled 'Spiel und Sport' to the great Enzyklopädie der mathematischen Wissenschaften in 1900. His interest in flight was later stimulated, in India, by the magnificent soaring and gliding of Himalayan birds whose actions in relation to their environment he did much to clarify. An article by him on natural flight in the Encyclopaedia Britannica placed much of this work on permanent record. Later still this interest was extended to human gliding and soaring and he greatly encouraged the sport in England in its early days.
Walker left Cambridge for India in 1904 to become director-general of observatories, which post he retained until retiring age in 1924. In 1908 he married May Constance (d. 1955), daughter of Charles Stephen Carter, gentleman farmer. They had one son and one daughter. Walker's administration of the Indian state meteorological service was most enlightened and in particular he gave their heads to the notable young scientists, like George Simpson and Charles Normand, whom he collected round him. From the beginning of his appointment he became much concerned with the vital problem for India of the variability of monsoon rainfall--the great Indian famine of 1899-1900 was much in people's minds--and he set out to find sound methods of forecasting the incidence of the Indian monsoon. This was a highly intractable problem for there was practically no quantitative theory of the monsoon nor therefore of its changes from year to year. Walker was thus led to seek empirical relations between antecedent events in and outside India and the Indian monsoon itself. Such relations are not difficult to find from the meteorological records over any given span of years but their persistence into the future, when lacking any theoretical basis, is uncertain. (Any two series of random numbers may show quite high but chance correlations over some part of their course.) Walker was well aware of the pitfalls pertaining to the method and he adopted the most stringent statistical tests of his analysis. Useful results were achieved but in spite of his tremendous effort to break it the monsoon problem really remained unsolved at the end of his term of office.
On retirement from India, Walker became professor of meteorology at the Imperial College of Science and Technology in London and he continued to explore the relations between weather in different parts of the world in a series of memoirs entitled 'World Weather' to the Royal Meteorological Society. He also engaged with students on a series of laboratory researches on the forms of motion in shallow fluids when heated gently from below (Bénard cells), and on the changes induced in these motions when a horizontal motion, varying with height, was imposed on the fluid. These experiments enabled Walker to identify the conditions of formation of many beautiful thin layer clouds (altocumulus) which commonly occur in the middle troposphere.
Walker retired from his chair to Cambridge in 1934 but remained active scientifically and in music (he was responsible for improvements in the design of the flute) until well over eighty years of age. He was president of the Royal Meteorological Society (1926-8), was its Symons gold medallist (1934), and editor of its Quarterly Journal (1935-41). He was elected FRS in 1904, appointed CSI in 1911, and knighted in 1924. These and other honours he wore lightly and ever remained modest, kindly, liberal minded, wide of interest, and a very perfect gentleman. He left Cambridge in 1950, living mainly in Sussex and Surrey thereafter. He died at Coulsdon, Surrey, on 4 November 1958.
P. A. SHEPPARD, rev. ISOBEL FALCONER
Sources
Indian Journal of Meteorology and Geophysics (Jan 1959)
G. I. Taylor, Memoirs FRS, 8 (1962), 167-74
private information (1971)
personal knowledge (1971)
CGPLA Eng. & Wales (1959)
Archives
Sci. Mus., corresp.
Likenesses
Maull & Fox, photograph, RS
J. Russell & Sons, photograph, RS
photograph, RS; repro. in Memoirs FRS, facing p. 167
Wealth at death
£8370 4s. 6d.: probate, 27 Feb 1959, CGPLA Eng. & Wales
[http://www.oxforddnb.com/view/article/36692]
GO TO THE OUP ARTICLE (Sign-in required)