The National Library of Scotland has been busy over the last few weeks adding more material to its online collection of maps covering the island of Ireland. Dating from 1859 to 1942, one bundle of 1,400-odd additions comes from the one-inch-to-the-mile scale and include towns and villages and land-use. By comparing map editions, you can readily see changes over time.
A second bundle dates from 1962–1971 and covers Northern Ireland.
Here's a bit more detail of the additions:
Engraved topographic maps - 1859–1917: Ordnance Survey's one-inch-to-the-mile engraved maps of Ireland total 1,069 sheets. These were the earliest maps at this scale covering all of Ireland, laid out in 204 sheets from north to south. For most areas, there were three main editions, as well as different styles of maps, sometimes showing relief with contours, or with hachures. The multiple editions of the series are particularly useful in providing an overview of significant landscape changes relating to villages and towns, the development of roads and railways, and changing patterns of woods and estate parkland.
Administrative maps - 1898–1902: A set of administrative maps at one-inch-to-the-mile scale, covering all of Ireland. These show the boundaries of Urban Districts, Rural Districts, County Boroughs, and County Boundaries, as defined by the Local Government (Ireland) Act of 1898. This upload covers 202 sheets.
Coloured topographic military maps - 1940–1942: From the War Office, this military map series was rapidly compiled during the Second World War from the latest available Ordnance Survey one-inch and half-inch to the mile mapping. It provides a useful overview of the landscape, with some sheets revised to show the latest road information, whilst others carry an overprint showing bogs, and relief in layer-colours.
Northern Ireland Grid Series, 1962–1972: Mapped at 1:10,560 / 1:10,000, the Grid Series is the largest topographic mapping covering all areas in Northern Ireland from the 1960s to the present day. These 285 sheets provide a clear, detailed view of the landscape, including roads, buildings, fields, administrative boundaries, water features and vegetation.
View these maps on the Library's interactive map of Ireland,