This work is built on five years of meticulous research at national archives in Dublin, London, and Belfast and at the Military Archives in Dublin and the Ordnance Survey’s archives at Phoenix Park. The research is enriched by personal interviews and the narratives of those directly involved in this remarkable journey. The following is a selected bibliography:

Alder, Ken
The Measure of All Things: The Seven-Year Odyssey and Hidden Error That Transformed the World
Free Press, 2003

Andrews, J. H.
A Paper Landscape: The Ordnance Survey in Nineteenth-Century Ireland
Clarendon Press, Oxford, 1975

Andrews, J. H.
Shapes of Ireland: Maps and Their Makers, 1564–1839
Geography Publications, Dublin, 1997

Berggren, J. L. and Alexander Jones
Ptolemy’s Geography: An Annotated Translation of the Theoretical Chapters
Princeton University Press, 2000

Borre, Kai
Fundamental Triangulation Networks in Denmark
Journal of Geodetic Science 4 (2014): 74–86

Butler, Samuel
A Statistical Account of the Parish of Tamlaght Ard (Magilligan), Diocese of Derry
Manuscript (PRONI), Magilligan, 1824

Clarke, Alexander Ross
Account of the Observations and Calculation of the Principal Triangulation (and of the Figure, Dimensions and Mean Specific Gravity of the Earth as Derived Therefrom)
George Edward Eyre and William Spottiswoode, London, 1858

Close, Colonel Sir Charles
The Early Years of the Ordnance Survey
Institution of Royal Engineers, 1926

Crane, Nicholas
Latitude: The Astonishing Adventure That Shaped the World
Penguin Random House, 2021

Day, Angelique and Patrick McWilliams (eds.)
Ordnance Survey Memoirs of Ireland, Vol. 11: Parishes of County Londonderry III (131–5)
Institute of Irish Studies, Queen’s University Belfast, 1991
(Memoir by John O’Donovan and George Petrie, 1835)

The Economist
The Economist Style Guide
The Economist, London, 2005

Gordon, Alan
The Regiment That Mapped the World: The Story of the 42 Survey Engineer Regiment
Royal Engineers, 2021

Grann, David
The Wager: A Tale of Shipwreck, Mutiny and Murder
Simon & Schuster, 2023

Haasbroek, N. D.
Gemma Frisius, Tycho Brahe and Snellius and Their Triangulations
Rijkscommissie voor Geodesie, Delft, 1968

Kirwan, Richard
If Maps Could Speak
Londubh Books, 2010

McLennan, John Ferguson
Memoir of Thomas Drummond, R.E., F.R.A.S., Under Secretary to the Lord Lieutenant of Ireland, 1835–1840.
Edinburgh: Edmonston and Douglas, 1867.

O’Brien, R. Barry
Thomas Drummond: Life and Letters
Kegan Paul, Trench & Co., London, 1889

O’Cionnaith, Finnian
The Origin of Ireland’s Ordnance Survey: Taxation, Townlands and Topography
Four Courts Press, 2024

Owen, Tim and Elaine Pillbeam
Ordnance Survey: Mapmakers to Britain since 1791
Ordnance Survey, 1992

Portlock, J. E.
Memoir of the Life of Major-General Colby
Seeley, Jackson & Halliday, London, 1869

Seymour, W. A. (ed.)
A History of the Ordnance Survey
Dawson, 1980

Smith, Adam
An Inquiry into the Nature and Causes of the Wealth of Nations
London, 1776

Sobel, Dava
Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time
Fourth Estate, London, 1998

Wainwright, Alfred
The Eastern Fells
Frances Lincoln, 2009 (special edition)

Taylor, W. R.
An Outline of the Re-Triangulation of Northern Ireland
HMSO, Belfast, 1967

Yolland, William
An Account of the Measurement of the Lough Foyle Base with Its Verification and Extension by Triangulation
Board of Ordnance, 1847