Rothamsted in the Making of Sir Ronald Fisher Sc.D., F.R.S
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Rothamsted in the Making of Sir Ronald Fisher Sc.D., F.R.S. John Aldrich Economics Department University of Southampton Southampton SO17 1BJ UK e-mail: [email protected] Abstract In 1919 the agricultural station at Rothamsted hired Ronald Fisher (1890-1962) to analyse historic data on crop yields. For him it was the beginning of a spectacular career and for Rothamsted the beginning of a Statistics Department which became a force in world statistics. Fisher arrived with publications in mathematical statistics and genetics. These were established subjects but at Rothamsted between 1919 and -33 he created the new career of agricultural research statistician. The paper considers how Rothamsted, in the person of its Director Sir John Russell, nurtured this development while supporting Fisher’s continuing work in mathematical statistics and genetics. It considers too how people associated with Fisher at Rothamsted, including assistants Wishart, Irwin and Yates and voluntary workers Tippett, Hoblyn and Hotelling contributed to establishing Fisherian statistics. September 2019 1 Introduction In 1919 a 29 year-old Cambridge mathematics graduate with no established profession started at Rothamsted Experimental Station; he died in 1962 “the most famous statistician and mathematical biologist in the world”—thus Irwin et al. (1963: 159). Sir Ronald Fisher Sc.D., F.R.S. was Balfour Professor at Cambridge when he was knighted and had been Galton Professor at University College but the higher doctorate and Fellowship of the Royal Society came when he was at Rothamsted. Ronald Aylmer Fisher would be another Galton and Balfour Professor but at Rothamsted he was the first Chief Statistician or even statistician. Between 1919 and 1933 he made a career for himself by creating the career of agricultural research statistician. What he did is sketched by Irwin et al. and detailed in Box’s Life (1978) and in numerous technical studies—see Aldrich (2003/19)—but here I look behind the what to consider how Fisher managed—and was helped—to do it. Rothamsted stimulated him to do the work in agriculture and, more surprisingly, encouraged the work in mathematical statistics and genetics that brought him fame; it also helped create a following to bestow that fame. Fisher at Rothamsted sits in larger histories—of mathematical statistics, of mathematicians in British statistics, of statistics in agriculture and of agricultural science in Britain—and I have drawn on these literatures.1 I also glance at parallel lives and institutions and at Fisher’s experience after Rothamsted, developing Box’s (1978: 96) observation that he “was never happier professionally than during the years he spent there.” But I start with the ideas, people and institutions that together provided a launch-pad for the career of agricultural research statistician. 1 Thus Parolini (2015a) tells much of the present story from another angle. 2 1 A platform for the agricultural research statistician In 1948, when Frank Yates Fisher’s successor at Rothamsted was made FRS, he told Sir John Russell that the award “must be personally gratifying to you also in that you are as it were the god-father of agricultural research statistics.”2 That god-paternity went back to the time when, as Director, Edward John Russell (1872-1965; FRS 1917), contemplated the “mass of valuable data” from the Rothamsted experiments and looked forward to a time when “conditions become more normal.”3 Russell (1917: v) mused, “I cannot help thinking that the application to them of modern statistical methods would yield information of high value both to the man of science and to the practical agriculturist.” Men of science were already using statistical methods and I recall their work as it prepared the way for the office of agricultural research statistician and treated problems—especially in field experiments and agricultural meteorology—later taken up by Fisher. I start with the research setting and the sources of statistical expertise before proceeding to the scene at the close of the Great War. The pre-war agricultural research community was small and, though dispersed across experimental stations, agricultural colleges, universities and even businesses, strongly inter-connected with findings disseminated through academic, trade and official publications. The leading professional forces were Rothamsted Experimental Station, the Cambridge University School of Agriculture and the Journal of Agricultural Science—of this last Russell (1966: 286) wrote, “for some forty years it published almost all the chief papers in agricultural science in Great Britain.” Rothamsted, the life work of John Lawes and Henry Gilbert, started in 1843 while the 2 Yates was replying to Russell’s letter of congratulation. 3 For Russell see his Autobiography (1956) and Thornton’s (1966) memoir. 3 School and journal dated from 1899 and 1905 respectively. Public support for agriculture and agricultural research—much increased after 1910—was through the Board of Agriculture and Fisheries, renamed Ministry in 1919.4 The Board had a branch responsible for agricultural statistics, i.e., the statistics of the agricultural sector—the numbers for agricultural economics.5 The numbers also interested the statisticians of the Royal Statistical Society and the close link between Board and Society is illustrated by the award of the Society’s highest honour, the Guy Medal in gold, to the Board’s P. G. Craigie (1843-1930) for “extraordinary services to statistical science in connection with the development of agricultural statistics.” 6 The Society’s domain was economic, demographic and social statistics with interest in statistical theory confined to a few, notably Edgeworth, Bowley and Yule.7 In 1869 the Journal had published a “statistical description” of some Rothamsted experiments—by Frederick Purdy, a compiler of Poor Law statistics—but this was an isolated venture and agricultural experiments only became the Society’s statistics in the 1930s; see §7 below. The Society’s statistics did not stretch to matters like ascertaining “the conditions under which the plant grows and the soil supplies it with nutriment”—the purpose of 4 Russell (1966: ch. VII-VIII) and Vernon (1997) survey the entire scene. For Rothamsted, see Russell (1917), for the School, Wood (1922), and for the JAS, Bell (1980). 5 “On the Home Produce, Imports, Consumption, and Price of Wheat etc.” (1880a) the one paper written by Lawes and Gilbert for statisticians illustrates the point; Gower (1988: 181-2) comments on them as statisticians. 6 Craigie headed the Board’s Statistical, Intelligence, and Educational Branch; see Anon (1930). 7 Aldrich (2010a) examines the place of theory in the Society. 4 the Rothamsted experiments, as stated by Hall (1906: vi). However, in 1907 the Journal published a piece on agricultural meteorology which was agricultural science—cf. Lawes and Gilbert (1880b). The author of “Correlation of the weather and crops” was R. H. Hooker (1867-1944), a younger Society/Board figure abreast of modern biometric techniques like correlation.8 Hooker was developing a theme from “Seasons in the British Isles” by Napier Shaw of the Meteorological Office—the Society maintained a watching brief for all official statistics. Hooker’s paper did not realise Craigie’s expectation that it would be “the beginning of a series of papers in which the practical knowledge of agriculturalists and the theoretical methods of arithmetical expression might be brought together” and Hooker’s research into crops and weather proved of more interest to meteorologists.9 Agricultural researchers looking for statistical methods turned to the theory of errors or to biometrics.10 Error theory/least squares theory had been developed by mathematicians in the early nineteenth century for measurement problems in astronomy and geodesy and was widely taught and disseminated in textbooks of different levels while biometrics was newer and less accessible. The leader of the biometricians, Karl Pearson (1857-1936) of University College, was a great proselytiser but he was not directly involved with agriculture and his “journal for the statistical study of biological problems”—Biometrika—published its first specifically 8 See Aldrich (1995: 370ff.) for the time series correlation analysis developed by Hooker and his friend Yule. Hooker’s life is recalled by Yule (1944). For Yule see below. 9 The first reference to Hooker in the JAS was Fisher (1921). More immediately Gosset responded to a point raised in the discussion with his “Probable error of a correlation coefficient” (1908b). Hooker eventually became President of the Meteorological Society. 10 For the theory of errors and biometry see Stigler (1986). 5 agricultural article in 1923. However, Gosset and Yule—who may be thought of as Fisher’s forerunners—had been Pearson’s students and two of his American followers, the zoologist Raymond Pearl and botanist J. Arthur Harris, worked in experimental stations and took an interest in agricultural experiments.11 Pearson’s core interest was in biology, including eugenics, and he advocated the use of statistics in medicine though his influence there was chiefly through his disciple Major Greenwood who was at the Lister Institute from 1910. 12 A harbinger of the post-war development of agricultural statistics as the statistics of agricultural experiments was a session on “error in agriculture experiment” jointly organised by the Agricultural and the Statistical Sections for the 1910 British Association conference.13 The papers reflected thinking on how the theory of errors could be used in agricultural research and, in particular, the inferential possibilities of the probable error—how it could make precise statements like this from Hall (1909b: 362), “Plot 12 is probably better than Plot 3 by more than 8.1, and less than 11.9 per cent.” The prime movers were not marginal or junior figures but A. Daniel Hall (1864-1942; FRS 1909), Russell’s predecessor as director of Rothamsted and reviver of its fortunes after the deaths of the founders, and Thomas Wood (1869-1929; FRS 1919), professor of agriculture at Cambridge, both founding editors of the JAS.