Engineer, architect, builder, projector, and author of A Treatise of Building in Water (1776), of Dublin. The biographies of Semple which appear in APSD, The Builder and DNB are largely based on the fragments of information which he lets fall in his Treatise and in the expanded reissue of 1780, published in Dublin under the title Hibernia's Free Trade. The APSD gives the date of Semple's birth as circa 1700, presumably because, when writing the Treatise, he claimed that he had been picking up information about the techniques of mortar making from his childhood onwards 'for upwards of sixty years'. Semple also claimed that his father was a builder's workman 'about the year 1675', and that 'the whole of my Scholarship, except what little I got whilst I was a meer Child, was acquired within the Compass of six winter weeks, in the thirteenth Year of my Age'. However Frederick O'Dwyer believes that Semple's hints at an uneducated working-class background are misleading, for he had family connections with the landed gentry in the west of Ireland and with the Established Church.
Semple says nothing about his early career in the Treatise; the first episode to which he refers - in the 1780 edition - is a tour made in August 1739, when he visited Sir John Bingham at Castlebar, Co. Mayo, John Bingham at Newbrook, Co. Mayo, 'Mr Bowen's' (perhaps Christopher Bowen of Hollymount, Co. Mayo) and Arthur French at French Park, Co. Roscommon. Presumably all these visits were connected with actual or potential commissions. His first securely documented commissions both date from 1749, when he designed and built the spire of St Patrick's Cathedral, Dublin, and when his plans for St Patrick's Hospital, Dublin, which he had prepared the previous year, were approved by the Board. In the Treatise he mentions the works on which he was engaged in 1751 when he was first approached about rebuilding Essex Bridge; these were St Patrick's Hospital, two houses in Capel Street for Dr Edward Leigh, treasurer of St Patrick's Cathedral, a house for Arthur Newburgh, a house for the Archbishop of Dublin (Newbridge, Co. Dublin) and Ramsfort at Gorey, Co. Wexford.
The story of the building of Essex Bridge in 1753-1755 forms the principal subject of the Treatise. Semple recounts how, although he had a 'fine and valuable' collection of books, he had great difficulty in finding information about making the coffer-dam which he proposed to use for laying the foundations. He went to England twice, first to buy more books in London, and then, in May 1752, to consult Charles Labelye, the designer of Westminster Bridge, and WILLIAM ETHERIDGE and Thomas Preston, who were at that time building the piers of Ramsgate harbour, but none of them was able to give him any advice or encouragement. Eventually he found the information he needed in the newly-published fourth volume of Bernard Forest de Bélidor's Architecture Hydraulique which was sent him from France. The bridge, closely based on Westminster Bridge, was begun in January 1753 and finished in May 1755.
Semple appears to have had a restless, energetic, enquiring temperament; as he wrote of himself in the Treatise he 'had on many occasions… felt a great desire to acquire knowledge in difficult matters of arts and science' but 'whenever they grew easy and familiar to me I could no longer perceive in them the same charms which had captivated me'. He simmered with ideas and projects. Having read in Alberti that a bridge should be the same width as the road leading up to it, he proposed a new broad street leading from Essex Bridge to a new square in front of Dublin Castle, and published a map of the scheme in 1757. It was the realization of this new street which brought about the appointment of the Wide Streets Commissioners in 1758.
Semple also had an interest in canals; he recalls that in 1755 a suggestion that he should be nominated Controller of Inland Navigation, with responsibility for reporting on the works of all the canals in Ireland was 'shamefully circumvented'. In the winter of 1755, when the best route for a navigation to link the Liffey and the Shannon was under debate, he made a tour to inspect the alternatives for himself, at the same time collecting material for his schemes for the improvement of Ireland. He made a set of charts of Dublin Bay 'based on some of the most authentic surveys of this harbour for some hundred years past' and including own proposals for developing the bay which he presented to the Ballast Board in 1762. The Treatise includes a plan for developing a harbour at the Downs, near Deal, or Walmer in Kent, while in Hibernia's Free Trade he proposes the construction of two great roads linking Derry to Cork and Dublin to Galway.
It was apparently in the winter of 1755 that Semple fell ill and was 'obliged to retire to the Country in a deplorable Condition…particularly afflicted with the Gravel and Rheumatism'. The collapse of his health was thought to be due to his exertions in building Essex Bridge, and in 1761 he received a grant of £500 from the government. In 1764 he claimed in the Court of Exchequer that money was due to him from the Corporation 'for services done at Essex Bridge, the Little Green, and the committee of directors of the Ballast Office'. Some ten years after his enforced retirement, 'having…got the better of some of my disorders', he returned to Dublin and started to write A Treatise on Building in Water, which was published in Dublin in 1776 and reissued in Dublin and London in 1780 with a preface and a third part in which he expounded the advantages of free trade. The Dublin reissue appeared under the title Hibernia's Free Trade: or a Plan for the General Improvement of Ireland, peculiarly adapted to a Free Trade.
Semple died at his house in Queen Street, Dublin, in April 1782. He was married but had no male children. He was the brother of JOHN SEMPLE . According to Cox, GEORGE SMITH was his pupil.
Addresses: Queen Street, 1763-1775; 53, Queen Street, 1776-1782.
See WORKS, BIBLIOGRAPHY.
APSD 7, S, 51.
B 35, 8 Dec 1877, 1217-1219.
Frederick O'Dwyer has written a revised entry for the Oxford DNB. Semple also has an entry in A.W. Skempton et al., A Biographical Dictionary of Civil Engineers in Great Britain and Ireland I (2002), 599-600.
See note 4.
See note 4.
Awaiting further info. from F.O'D.
Hibernia's Free Trade, 163.
Aidan O'Boyle has pointed out that a new church was in contemplation at Castlebar; John Bingham of Newbrook had married an heiress the previous year.
See note 1, above, M. Craig, Dublin 1660-1860 (1952), 139. and M. Craig, ed., The Legacy of Swift(1948), 32.
Treatise, 27; Christine Casey, The Buildings of Ireland: Dublin (2005), 443-4.
Hibernia's Free Trade, v.
Hibernia's Free Trade, v-vi; Edward McParland files (IAA, Acc.2008/44) state that there is an MS book on canals by Semple in NLI, but it does not appear in the library's on-line catalogue.
Skempton, op. cit, above, 600, citing G.Daly, 'George Semple's charts of Dublin Bay', Proceedings of the Royal Irish Academy (1993), 81-105.
Hibernia's Free Trade, 168-9,177ff., Pl.64
Hibernia's Free Trade,vi.
APSD, loc. cit, above, citing Liber Munerum Hibernia Pt. 6, fol. 57; Faulkner's Dublin Journal, 14-17 Nov 1761. A copy of his printed petition to Parliament is in PRONI, D562/7704, together with a printed certificate from the overseers of the bridge. dated 19 Oct 1761, stating that hehad had carried out his duties to their satisfaction (D562/7702).
Treatise, vi; cccording to Craig, these years were actually spent 'prospecting in the West of Ireland in connexion with the canal-craze'.
CARD XI, 186; Hibernia's Free Trade, vi.
For a more detailed description see P.W. Nash & al., British Architectural Library…Early Printed Books 1478-1840 IV (2001), 1794-5; extensive extracts from the text were published in IB 15 between June and December 1873 (pp.144, 162, 178, 192, 204, 216, 236, 244, 266, 274, 286, 302, 320, 334.
Faulkner's Dublin Journal, 13-16 Apr 1782.
Information from F. O'Dwyer.
R.C. Cox & M.H. Gould, Civil Engineering Heritage: Ireland (1998), 93.
From Wilson's Dublin Directory.