The Ordnance Survey in Ireland

On this week's programme, we’re looking back at the early years of the Ordnance Survey in Ireland. Just over 200 years ago, the British government launched one of the most ambitious projects ever undertaken here: to map the entire island, townland by townland, in unprecedented detail.

The Ordnance Survey produced maps that remain a cornerstone of Irish history - capturing not only the features and contours of the land, but also its names, language, and heritage. On tonight’s show, we’ll explore the story of that vast mapping project - from its beginnings and political purpose, to its lasting influence today.

To begin this evening – our reporter Marc McMenamin finds out more about how this project began, and why it’s one of the most significant projects in Ireland’s history. He speaks to Dr Angela Byrne of the Royal Irish Academy and Professor Breandán Mac Suibhne of the University of Galway.

The Ordnance Survey was one of the great undertakings of the 19th century. It was a project of great technical ambition, which shaped how Ireland was defined and understood, both on paper and in practice. To explore this story, from its beginnings in Britain, through the mapping work in Ireland - the politics, the placenames, and the legacy the OS left behind, Myles is joined in studio by three guests.

Dr Finnian O’Cionnaith is a qualified land surveyor, and the author of the book The origin of Ireland’s Ordnance Survey, published last year by Four Courts Press, to mark the 200th anniversary of the beginning of the project.

Dr Aengus Ó Fionnagáin is a lecturer in Irish at the University of Limerick, he worked on the OS200 Project, which created a digital archive of OS maps and texts.

And Dr Paddy Prendergast, Founder of Property Boundaries Ireland, who for fifteen years was Commanding Officer, Survey Company, Corps of Engineers with the Irish Defence Forces.

Locating Bench Marks, Preserving Heritage

It was in the late 1830s that surveyors started adding a new dimension to the maps: height.

"Benchmarks" also known as "crow's feet", were chiselled into buildings, walls and bridges – to record the height above mean sea level. Corresponding marks and numbers on the maps show the height of the land at those exact points.

Some of these benchmarks still survive today across this island – though many have been lost or damaged over time. Now, a research team at the University of Limerick are seeking to locate and record the existing bench marks in Limerick, and the local surrounds – with a plan to later go national.

The project is called Locating Bench Marks, Preserving Heritage. You can go to their website to join in on the hunt for bench marks and contribute to this new database. To talk about all this, Myles is joined from our Limerick studio by Dr Catherine Porter, a historical geographer at UL.

Catherine was also a Principal Investigator on the OS200 project. You can explore some of the maps and texts discussed throughout this programme at the OS200 online resource. There you’ll find the maps; letters rich in commentary on the people of Ireland; memoirs; the name books, and more.

This material uncovers hidden and forgotten aspects of the life and work of OS workers as they mapped and recorded landscapes and localities. That project was led by The University of Limerick and Queen’s University Belfast; and supported by the Royal Irish Academy, the Public Records Office of Northern Ireland, the National Library of Ireland, and the Digital Repository of Ireland.