The text accompanying the maps comprises an introductory essay, topographical information on the town as a whole and its component parts, selected documentary and literary extracts where appropriate, and a bibliography. The maps and topographical information are derived directly from primary sources and to that extent are incapable of becoming out of date. But readers may also expect to be given an interpretation of the sources, and this is the role of the introductory essay. Each town is described in relation to its physical site and setting, and its development is reviewed in chronological sequence from the beginnings of urban life to the end of the nineteenth century, with a brief indication of its twentieth-century history. The essay is intended to deal primarily with the form and layout of the town as expressed in the accompanying maps. Individual buildings may receive attention as topographical entities, but the atlas does not usurp the functions of an archaeological or architectural survey. In the same spirit, political and socio-economic factors are introduced in so far as they seem relevant to an understanding of the townscape and not as ends in themselves. The bibliography lists all important items devoted to a single town, especially those of topographical relevance, and is not necessarily confined to works cited in the footnotes. Other sources mentioned in the footnotes are not separately tabulated, except where their titles have been abbreviated in a way that requires explanation. Abbreviations of more general application are listed inside the back cover of each fascicle. Grid references follow the Irish National Grid as shown on current Ordnance Survey maps, and throughout the atlas placenames are spelt as in the maps of the Ordnance Survey of Ireland or the Ordnance of Northern Ireland.Examples from Topographcial Information:
- IHTA, no. 10, Kilkenny
- IHTA, no. 11, Dublin, part 1, to 1610
- IHTA, no. 12, Belfast, part 1, to 1840
- IHTA, no. 13, Fethard
- IHTA, no. 14, Trim
- IHTA, no. 15, Derry~Londonderry