“…The most famous of these series is undoubtedly the sunspot index, first investigated empirically by Newcomb (1901) and then by Schuster (1906) using periodogram analysis, a technique that was extended by Larmor and Yamaga (1917). Yule (1927) later used the series to illustrate his autoregressive scheme, which was subsequently generalised nonlinearly by Moran (1954): later contributions to the modelling and prediction of the sunspot index have been provided by, for example, Granger (1957), Craddock (1967), Morris (1977) and Yoon (2006). Consistent with this historical perspective, over the last decade I myself have analysed various temperature series using a variety of statistical models, usually with the aim of extracting the trend component.…”