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The Convict Trail Project

British Ordnance Survey


Background for the New Colony

The historical background to the involvement of certain Army officers is an interesting facet of the construction of the Great North Road. They were responsible for the survey of the route, the implementation of orders for convict involvement and the planning for the road, on the spot decision making and the GNR construction. What possible training might they have had in such diverse civil and military engineering tasks?

It could have been that there were strong moves afoot in Britain to do with the pressure of potential and actual wartime conditions in the late 18th and early 19th Centuries. Britain was under threat from Napoleon just as many other countries were invaded so that it was essential for the military organisations to have a sound basis for the mapping of the country and the construction of harbours and forts. It is instructive to delve into the British scientific tradition and the establishment of two permanent bodies responsible for survey, mapping, drafting and ordnance aspects of British duties of care for the realm and the land, not only at home but at overseas colonies.

The work of officers, such as Major Thomas Mitchell and Lieutenant Percy Simpson, both in the new Colony and earlier in other overseas postings, makes it apparent that they had some rigorous training in surveying, drafting and cartography, as well as in construction operations – not just in military undertakings. Staff in Mitchell’s office must have had some excellent training in cartography. The following will assist in giving insight into the scientific and organisational preparations which were made in Britain in the later 18th and early 19th Centuries. It is almost certain that somehow the major efforts in Britain of that period set the scene for the intense activities in NSW in road building. It should be noted that we should give attention to the other ranks who must have had background as artificiers, draftsmen and tradesmen, providing the essential support for the extensive operations. Some may well have been convicts themselves and that is worth investigating too.

The British Board of Ordnance

The Board of Ordnance, to which the national survey of Great Britain owes its name, was already one of the most ancient institutions in the country by the late 18th Century. Its roots have been traces to the middle ages and its beginnings were connected to the establishment of the Royal Arsenal at the Tower of London. … The primary duty of the Board of Ordnance, described by its historians, was first as custodian of lands, depots and forts required for the defence of the realm and its overseas possessions; and second as the supplier of munitions to both the Army and the Navy. At the same time, the Board was a civil organisation. This civil aspect began in the mid 18th Century to pay, maintain, educate, and organise military forces of its own – the so-called Ordnance Corp, of which the Artillery and Engineers are the best known and who were to officer the Ordnance Survey.

British military surveyors carried out geographical activities in Scotland up to 1756. When that work ceased, the activities were transferred to other regions where British policy was concentrated, owing to its military and colonial aspirations, in such places as Quebec, North America, Florida, Bengal and Ireland. Much of this work was entrusted to military surveyors to carry out military topographical surveying from the 1750s to the 1780s. One of the key men in all of this activity was William Roy who had been commissioned as a Lieutenant in the Engineers in 1756 after a period as a civilian assistant in the Board of Ordnance. His experience in Scotland and subsequently saw him serving in 1760-62 as Deputy Quarter Master General under the Duke of Richmond, Master General of the Board of Ordnance. By 1766, Roy had been appointed by Royal Warrant of 31 July 1765 as Surveyor-General of Coasts and Engineer for making and directing Military Surveys in Great Britain. … At this point, we must skip a couple of decades but the details are readily available in the two volumes quoted above.

A Scientific Poser

In 1783, Roy was given an opportunity, under somewhat surprising circumstances, to foster his cherished belief in the need for a national survey organisation. In 1783, the geographical position of the Royal Observatories in Paris (France) and in Greenwich (England) saw a difference of opinion between astronomers of the two countries that amounted to nearly 11 seconds for longitude and 15 seconds for latitude. It was not a new problem and earlier attempts to resolve the issue by means of astronomical measurements had been unsuccessful as reported in Philosophical Transactions of the Royal Society of London. The Director of the Paris Observatory was a foreign member of the Royal Society of London. He came up with the suggestions that scientists undertake a triangulation from the vicinity of the Greenwich Observatory to the coast near Dover and, from there by means of cross-channel observations, link up with the French triangulation completed in the area of Calais. …

What is of interest to Australians today is that the paper was passed to Sir Joseph Banks in his capacity as President of the Royal Society. Banks was no stranger to developments in geodesy and cartography but he turned to an even better qualified member, Major General William Roy, who had been elected into the Fellowship of the Royal Society in 1767. Roy responded quickly and positively with a proposal which was put before George III and, in April 1784, the Lords of the Treasury were instructed to implement the payments and the Royal Society confirmed the arrangement on 24 June 1784. Thus the vital Trigonometrical Survey was initiated and by 1791, through various vicissitudes, it was completed by 1791, just after General Roy’s death.

From Scientific Enterprise to Ordnance Survey At this point in time, the Board of Ordnance took over responsibilities which had begun under the direction of the Royal Society as a scientific enterprise. Under the pressures of war in the 1791-1800 period, the Board of Ordnance had learnt the lesson that adequate military intelligence required systematic geographical knowledge of the area of conflict. The Duke of Richmond took the decisive step to obtain approval for a national Ordnance Survey and appointed appointed Isaac Dalby who had been involved in the scientific trigonometrical survey up to its end. Two men were appointed from the Royal Artillery (Major Edward Williams and Lt. Mudge) of whom the most important one, though not in rank, was Lieutenant William Mudge, son of a notable West Country scientific family. Their first task was to remeasure the trigonometrical base set up by Roy in 1784 on Hounslow Heath. Mudge spent the following winter making drawings explanatory to the Trigonometrical Survey and, together with Williams and Dalby, established a pattern of activity for the future years of the Survey covering Kent and its neighbouring counties and Devon and Cornwall.

There is much of importance that happened in the years intervening to 1803 but a decision was taken in that year to use the Ordnance Survey in a field training school for the cadets destined for commission in the Royal Engineers and the Royal Military Surveyors and Draftsmen. The previous course for cadets at the Woolwich Academy may have been adequate for the Artillery but less so for the Engineers. Mudge, in spite of the pressure to get on with the West Country survey, gave this new task his personal attention. In Appendix 1, in Volume II (listed above in References) for Devon, Cornwall and West Somerset, a course of instructions in military surveying and plan drawing is set out.

Disastrous campaigns in Flanders in the 1790s also led to changes in the Quartermaster General’s department. In 1799, a Royal Staff Corps was raised to provide a force capable of a wide range of field engineering activities. Not only was this to be at a staff level but also through its companies of artificers and tradesmen, with skills relevant to the construction of field works and the laying down of roads and bridges. In 1803, the cartographic side was strengthened. Many of the Department’s staff had been trained at the new Senior Staff College at High Wycombe in field surveys and plan drawing. They were therefore well equipped to be occasionally employed in the Districts of Great Britain, either for the purpose of Military Surveys, examination of roads, marking ground for the encampment and exercise of Troops, or for the purpose of superintending and directing the progress of works for National Defence. All of these changed responsibilities for the Board of Ordnance and the Quartermaster General’s Department took place against the backdrop of the War that had broken out with the French Republic in 1793, with the changes well-established by the new 19th Century.





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Convict Trail MapThe NEW and updated map of the Great North Road is available in visitor information centres and is also available for download here.