'Observations and Statistics. An Essay on the Theory of Errors of Observation and the First Principles of Statistics.,' pp. 138-169 in: Transactions of the Cambridge Philosophical Society, Vol. XIV, Part II. Read May 25, 1885

First edition, journal issue in never-bound sheets, of the first and most important of Edgeworth's papers on the application of the statistical methods of the theory of errors to the social sciences and economics. "Of all the great economists in this book, he [Edgeworth] is (apart from Bernoulli and Slutsky) the only one to have made original contributions to mathematical statistics" (Blaug, Great Economists before Keynes (1986), pp. 69-71). "Francis Ysidro Edgeworth (1845-1926) was perhaps the statistician with the greatest mathematical abilities at the end of the 19th century" (Fischer, p. 122). "In 1883 began the series of papers that were to make [Edgeworth] the leading theorist of mathematical statistics of the latter half of the 19th century" (Stigler, The History of Statistics, p. 98). "He set himself to do at last what had been talked about and assumed possible for over a century but had never been accomplished: adapt the statistical methods of the theory of errors to the quantification of uncertainty in the social, particularly economic, sciences. In this he succeeded brilliantly" (ODNB). "Edgeworth's 1885 articles, particularly 'Observations and statistics' and 'Methods of Statistics', were widely noticed, both in England and on the continent, and until the end of the century when texts such as Bowley's Elements of Statistics began to appear, they served as basic references for the theory and application of statistical techniques to social and economic data" (Stigler, p. 297). RBH lists no copy of this paper (in any form). "The type of questions Edgeworth sought to treat and the difficulties he saw in their treatment were described in an 1884 review of a posthumously published collection of Jevons's papers, Investigations in Currency and Finance. Edgeworth commented upon the beautiful diagrams in the book, which he thought would assist the reader to estimate the probability that the differences in the averages for different weeks and months are not accidental: 'The question which has been just indicated, one of the most delicate in statistics - namely, under what circumstances does a difference in figures correspond to a difference of fact - comes up often in these pages. Thus Mr. Jevons, comparing the amount of bills created in the different quarters of the year, speaks of a variation to the extent of about six percent. as 'no great difference.' On the other hand, he regards it as noteworthy that, 'out of 79,794 bankruptcies which were gazetted from the beginning of 1806 to the end of 1860, 28,391 occurred in the second month of the quarter, 26,427 in the third month, and only 24,976 in the first month.' No doubt a similar disparity between 'heads' and 'tails' in the result of so many throws of a coin would prove a cause, a want of symmetry in the coin. But our knowledge of the behaviour of tossed coins rests at bottom upon observation and experiments such as those which Mr. Jevons once performed. That what is true of games of chance is true of bankruptcies is not to be assumed without examination.' "Edgeworth was to provide this examination. "Edgeworth's key work on this topic was contained in a series of four papers read in the year 1885. The first of these, 'Observations and statistics: An essay on the theory of errors of observation and the first principles of statistics,' was read on 25 May 1885 to the Cambridge Philosophical Society. It concentrated on statistical theory and summarized and extended his work of the previous two years. The second paper, 'Methods of statistics,' was read a month later, on June 23, to the international gathering to celebrate the jubilee of the [Royal] Statistical Society. It was concerned with methodology and presented, through an extensive series of examples taken from all manner of fields, an exposition of the application and interpretation of significance tests for the comparison of means. Much of the material in these two papers was presented at least in outline in Edgeworth's.…