The Chronology of Ancient Nations, written in the 10th Century AD by the Islamic scholar al-Biruni, provides a monthly calendar of weather and climatic information translated from ancient Greek, Egyptian and Roman sources. The descriptive citations of heat and cold, hydrometeors and wind were extracted from the calendar for interpretive analysis. Assessment of data quality requires examination of the calendar used by al-Biruni, the translations available, the sources cited, the period described, and the locations mentioned. Innumerable difficulties were encountered in analysis of the extracted data and eventually only sources relating to Egypt from cl00 BC to cl00 AD were considered seriously as a potential usable data set for historic climate reconstruction. Although requiring a number of assumptions, information extracted from the Chronology suggests that precipitation distribution and wind direction in the identified period differed from those of the present.
For eras prior to the instrumental period, the reconstruction of climate in historic times has drawn extensively upon many proxy data sources including contemporary literature. As illustrated by the work of Ladurie (1972) and , careful analysis of a variety of climatic data sources provides highly meaningful results. In many instances such analysis has served to enable a sequence of climatic variation to be identified. Similarly, and as demonstrated by , the ancient literature often contains rational scientific explanations of observed atmospheric phenomena. At the same time, while much of value has been derived, the interpretation of historic writings is fraught with problems when attempting to reconstruct climate. As Ingrain et al. (1981) note, 'These sources are of varying quality, and a rigorous historical methodology is required in order to reject unsuitable and inadequate material, and to extract the maximum amount of information from what remains'. The historic writing analyzed in this paper certainly faces the problem of attempting to differentiate between what is meaningful, and what must be rejected.
Most detailed research using documentary sources concerns climate of the last 1000 years. Although studies of ancient Chinese climate (e.g. ) and those of Roman and Classical Greek times (e.g. are available, they are less numerous. Even less well covered in the literature is the 9th-10th Century work published by Arab writers during the period of Islamic consolidation and the creation of Muslim libraries and centers of learning. Yet scholars of that time, who had access to a great variety of classical documents, provided a wealth of information of both the period in which they lived and the information contained in translations of classical works. While the ideas and thoughts of some