Cartography and Utilitarianism versus Culture: Thomas Colby of the Ordnance Survey of Ireland

Introduction

In the years 1824–46 one man, Lieut-Colonel Thomas Colby (1784–1852) of the Royal Engineers, dominated the Irish Ordnance Survey, established in 1824 by the British government to create a countrywide map for the purpose of removing inequalities in local taxation in Ireland. (See figure 1.) Inevitably, his main focus was cartography, and these new local maps helped to unveil the country to both the Irish and the British. Yet Colby and his second-in-command, Thomas Larcom (1801–79), later under-secretary in Ireland (1853–68), recognized that maps had their limitations and that the Survey provided a unique opportunity for collecting other sources of information of equal accuracy and importance. (See figure 2.) Over time this evolved into a scheme known as the “Memoir,” which aimed to chart the productive worth of the country and to illustrate and supplement the maps. Colby hoped that the combination of perfect maps and accompanying hard data would become the means for diffusing knowledge, stimulating the development of resources, and encouraging economic and social improvement in Ireland. He was a soldier, not a politician, yet he sanctioned and supported the Memoir, an extraordinary experiment whose significant “cultural” dimension was far removed from military duties and stood outside the limits of his formal orders. That alone would mark him as an unusual representative of the crown in Ireland. To this must be added his legacy as progenitor of a series of wonderful maps (at the very large scale of six inches to a mile) that delineated every nook and cranny of Ireland and that many still consult today. Both of these factors, allied to his having spent upward of twenty years in semi-permanent residence in Ireland, demand an examination of the character and work of a man who is less well known than his deputy Larcom.

Figure 1.

Thomas Colby

Figure 2.

Thomas Larcom

Thomas Frederick Colby was born on 1 September 1784 into a military family. After an upbringing in Wales and his schooling in Kent, he entered the Royal Military Academy and earned his lieutenancy in the Royal Engineers in December 1801. This was achieved despite the severe handicap of a head wound and the loss of his left hand following a pistol accident while he was in training. It says much for Colby’s aptitude for surveying that Sir Henry Mudge, head of the Trigonometrical Survey of Great Britain, received special permission from his political masters to retain him in the army.¹ Colby’s rise through the ranks was steady: he became a captain within six years, and his flair for mathematics and engineering saw him assist Mudge with the English Survey, following fieldwork in the wilds of Scotland. During this time he received an honorary doctorate from the University of Aberdeen. Colby was promoted to the rank of major in 1821, after his appointment as superintendent of the Trigonometrical Survey. No less a figure than the Duke of Wellington, head of the Board of Ordnance, confirmed Colby in his new post after extensive investigation of his suitability. This represented a strong vote of confidence in the knowledge and skills of a man who was only 36 years old, particularly in view of the august figure who had preceded him.² Within four years Colby’s attention was to be diverted to Ireland, which was to be mapped in its entirety.

Survey of Ireland

This work was assigned to the Ordnance department of the army and Colby was entrusted with its execution.³ One commentator believed that it was incumbent on Colby to reject conventional wisdom on methods of surveying formed from inquiries much more limited in scope than what was now proposed; he should tackle the prejudices that some in the scientific community bore against large-scale undertakings. Most knowledge to date had been acquired through finite surveys performed at no great pace and with small teams, whereas speed and precise accuracy were key requirements of the huge...