In 1825 the Ordnance Survey, under the direction of Lieutenant-Colonel Thomas Frederick Colby, began the daunting task of mapping Ireland topographically at a scale of six inches to the mile (1:10 560).
As a long-standing member of the Geological Society of London, Colby was well aware of the economic value that would accrue from making a ‘Geological and Mineral Survey’ in parallel with the topographical survey of Ireland (Herries Davies, 1983 pp.87).
Thus, on 14 November 1826 he appointed Captain J W Pringle to superintend the geological survey, and in March of the following year Pringle issued instructions for making geological and mineralogical observations.
Only limited progress was made owing to a lack of enthusiasm among the topographical field-parties, who for the most part had little interest in geology and no formal training in the subject.
Indeed, its unpopularity and the fact that the geological survey was not officially sanctioned by the Board of Ordnance led to the suspension of geological activity in September 1828.
This activity, conducted in the counties of Antrim and Londonderry, had amounted to little more than the collection of rock samples (noted in official correspondence from September 1826), with their locations plotted onto a crudely coloured six-inch map, and the drawing of two geological panoramas (Herries Davies, 1983 pp.88–95; Andrews, 1975 pp.67).
Despite this setback, Colby was eventually given approval to appoint Lieutenant (soon to become Captain) Joseph Ellison Portlock to resume the geological survey in January 1830.
Portlock had good geological credentials, but he was too pre-occupied with the primary triangulation of Ireland to give much attention to geological matters until late in 1832 (Portlock, 1843).
It was about this time that Portlock set about establishing a geological branch of the Ordnance Survey of Ireland.
In 1834 he was asked to contribute to an Ordnance Survey memoir describing the parish of Templemore, which includes most of the city of Londonderry.
A provisional edition of this memoir was printed in 1835 for the annual meeting of the British Association for the Advancement of Science, which took place at Dublin in August of that year.
The memoir included a hand-coloured plate depicting the geology of the parish of Templemore at a scale of one inch to the mile, being the first official geological map to be published for any part of Ireland (Figure 3).
Formal publication of the memoir did not follow until 1837 (Colby, 1837). In this same year Portlock was able to set up an office, museum and soils laboratory at Belfast, thus establishing the Geological Branch for the first time as an organised entity (Andrews, 1975 & 155; Herries Davies, 1983, pp.100).
Financial and other considerations unfortunately led to the closure of Portlock’s department in February 1840, although he was given time to complete his monumental Report on the geology of the county of Londonderry and of parts of Tyrone and Fermanagh, published in February 1843 (Figure 4).
Official geological activity in Ireland thus effectively came to an end for the second time, although Colby did not give up without a struggle (Herries Davies, 1983, pp.106–22).
The Irish geological survey was not to be formally reinstated until the passing of the Geological Survey Act of 1845, which established the Geological Survey of Great Britain and Ireland under the general directorship of Henry De la Beche.
Portlock’s Report, accompanied by a fold-out geological map at a scale of half an inch to the mile, and his contribution to the Templemore memoir, were the only published products of this early attempt at an official geological survey of Ireland.
It should not be forgotten that Richard Griffith published his geological map of Ireland in 1838 and 1839 utilising a topographical base specially prepared by the Ordnance Survey.
From the very beginning he had kept a close watch on the activities of the Survey in Ireland, but maintained a self-interested scepticism of its ability to produce geological maps of a quality comparable to his own (Herries Davies, 1983, pp.48, 91-2).
In 1814 John MacCulloch was appointed geologist to the Trigonometrical Survey (as the Ordnance Survey was then called) with orders to locate areas in Scotland where the geology might cause abnormal deflections of the plumbline, so that they could be avoided in the geodetic measurements to establish a meridian for the construction of the one-inch map.
At the same time he was asked to discover a mountain more suitable than Schiehallion in Perthshire for determining the mean density of the Earth (Flinn, 1981).
MacCulloch used this opportunity to carry out a more wide ranging geological survey of the country in furtherance of observations begun by him in 1811 while employed by the Board of Ordnance as chemist (Cumming 1984).
According to his own testimony much of this work was done in his own time and at no additional expense to the Ordnance.
In June 1821 he submitted a proposal to the Board for completing and publishing a ‘mineralogical map’ of Scotland. Nothing came of this, notwithstanding an earlier show of melodrama, made in the presence of T F Colby, in which he had talked of hanging and shooting himself if he were not permitted to finish the map! (Figure 5; Flinn, 1981).
In 1826 he was encouraged to apply directly to the Treasury for financial support, and in this he was successful.
On 4 July the Treasury issued a minute sanctioning the continuation of the survey and expressing the view that such a map ‘must prove, not only highly interesting in a scientific point of view, but of considerable practical utility to many branches of industry connected with the mineral kingdom’ (Eyles, 1937).
MacCulloch’s survey appears to have been finished by about 1832 (having thus taken at least 18 years to complete), but it required a memorial from the Highland and Agricultural Society of Scotland before the Treasury could be induced to publish the map.
A principal hindrance had been the inadequacy of the topographical base published by the firm of Arrowsmith, upon which MacCulloch had been obliged to plot his geological lines, and about which he made continuous complaint (the Ordnance Survey did not begin systematic topographical mapping in Scotland until 1846, having abandoned its earlier attempt in 1828).
MacCulloch’s geological map was eventually published by Arrowsmith in 1836, a year after its author had died following a carriage accident while on his honeymoon, aged nearly 62. The map (Figure 6), accompanied by a memoir (MacCulloch, 1836), is an impressive achievement, being at the scale of four miles to the inch, but seems not to have had a very lasting impact (Judd 1898).
MacCulloch’s all too characteristic contempt for fossil evidence (as for much else) made the result less useful to the stratigrapher than it might otherwise have been. (For a more generous assessment of MacCulloch’s legacy, see Bowden 2009).
MacCulloch’s travel expense claims for his ‘mineralogical’ survey proved to be so exorbitant that the Treasury was induced to undertake a detailed enquiry, the results of which appeared in a Parliamentary Paper in 1831 (Eyles 1937).
The memory of this injury to the public purse was to resurface in December 1839 when De la Beche asked the Board of Ordnance for permission to spend the winter months in London for the purpose of arranging his notes.
The Board stipulated that De la Beche’s travel allowance be suspended for the period of his residence in London, and in adverting to ‘what occurred in respect to the Scotch Geological Survey,’ desired that ‘special care may be taken to prevent the occurrence of a similar fault in the English Survey’ (BGS Archives GSM 1/68, 320; North 1936, 82–5).
Bate, D G. 2010 Sir Henry Thomas De la Beche and the founding of the British Geological Survey. Mercian Geologist, 17 (3). 149–165.