Map of a Nation (29 page)

Writers of guidebooks also found the Trigonometrical Survey’s data
helpful
. A genre known as ‘the road-book’ had properly emerged in 1675, with John Ogilby’s
Britannia Depicta
. Over the next century road-books became sophisticated, compendious directories that provided their users with details of local inns, the times and fares of stagecoaches, and market days. In 1803 Daniel Paterson’s immensely popular
New and Accurate Description of the Roads in England and Wales, and Part of the Roads of Scotland
went into a
thirteenth
edition with a print run of 10,000 copies, and its editor consulted Britain’s foremost authorities on land-measurement to verify the book’s accuracy. He approached the surveyors and directors of the Post Office, the Commissioners of the Stamp Office, the engraver and Royal Geographer William Faden, the landscape gardener Humphry Repton, and the director of the Ordnance Survey, ‘the very ingenious Major Mudge’. William Mudge readily contributed the triangulation’s data, and
Paterson’s Roads
, as it was known, duly based its table of altitudes on ‘The Measurements of the Heights of Mountains and other Eminences, so accurately taken in the grand
trigonometrical
survey of the kingdom’. Mudge also assured its editor that he ‘may depend upon every information that the further progress of this great
undertaking
can supply’.

Map-makers and travel-writers were not the only ones to benefit from the Trigonometrical Survey. Once Williams, Mudge and Dalby started releasing information about their endeavour to the public through their articles for the
Philosophical
Transactions
(which maintained the scientific credibility of the work), and through their own published book, its data was hungrily drawn upon by readers with a variety of professional interests. In 1797 a physician called William George Maton published a book,
Observations Relative Chiefly to the Natural History, Picturesque Scenery and Antiquities of the Western Counties of England,
which used material from the Ordnance Survey’s published ‘Accounts’ to pinpoint the altitude of Ninebarrow Down, a long chalk ridge in the Purbeck Hills in Dorset. The Ordnance Survey’s levelling was said to have produced ‘for the first time … fairly good values for the heights of many British hills’. And two years later, in 1799, the economist Henry Beeke emphasised in his
Observations on the Produce of the Income Tax
how necessary it was that the exact areas of Britain’s counties should be precisely known when calculating their revenue from taxation. Beeke eulogised the ‘very excellent trigonometrical survey’, and plundered its data for this purpose. The Trigonometrical Survey was attracting a great deal of public attention and stimulating both popular fascination and professional engagement with its undertaking. For the first time, a clear sense of the precise size and shape of the country was emerging.

 

A
S THE YEAR
1795 began, the Ordnance Survey lost one of its most ardent devotees. Charles Lennox was sacked as Master-General of the Board of Ordnance. The Prime Minister, William Pitt the Younger, finally lost patience with his erratic temper, and Lennox’s old connection with the Reform movement and his antagonism to the King were proving liabilities during the politically fraught years following the French Revolution. Such a prominent military figurehead could not be seen to possess any links to republicanism. In his place, Charles Cornwallis, 1st Marquess Cornwallis, was persuaded to take up the Master-Generalship, which gave him an
executive
role in the Ordnance Survey. Best remembered today as the British general who surrendered at Yorktown in 1781 during the American War of
Independence, in 1795 Cornwallis had just returned from nine years in India, where his task had been ‘to give the crown the power of guiding the politics of India with as little means of corrupt influence as possible’. There, this corpulent, competent officer and administrator had restructured the East India Company, reformed the Bengali police, administered a system of land taxation and waged a successful military campaign against Tipu Sultan of Mysore, paving the way for British dominance in southern India. Cornwallis was an ardent royalist and on his return to Britain he was co-opted into the fight against Revolutionary France.

Mudge was initially dismayed by Lennox’s dismissal – the Trigonometrical Survey’s very existence had owed a lot to his fondness for cartography. But Mudge’s gloom soon proved unwarranted. Cornwallis may have lacked Lennox’s personal investment in the Survey, but he approached his role as Master-General with professionalism and, as he frequently sought Lennox’s advice about the Ordnance Survey, the voice of its founder continued to be heard. Nothing changed for the worse with Cornwallis’s arrival and in fact it was in 1795 that the Ordnance Survey became permanently involved in the activity for which it is now famous and loved:
map-making.

The first year of Cornwallis’s tenure saw the formalisation of the
previously
ad hoc collaboration between the Trigonometrical Survey and the Tower of London draughtsmen. What Mudge termed an official ‘union of the parties’ was instigated. The Tower draughtsmen were charged with
systematically
fleshing out the triangulation that was being conducted by Williams, Mudge and Dalby, and this group of civilian map-makers became known as the ‘Topographical’ or ‘Interior’ Survey. They were instructed to make detailed maps of piecemeal chunks of the landscape that were
separated
by major roads or rivers, whose measurements were rigorously checked against those of the triangulation. These jigsaw pieces would then be fitted together into a survey covering every inch of the kingdom, to be engraved and sold ‘for public use’. Although the resulting maps would not be referred to by their makers as ‘Ordnance Survey maps’ until at least 1801, the
following
pages will adopt this term. The moment when the collaboration was instigated was a crucial landmark in the Ordnance Survey’s history and arguably marks the birth of the institution as we now know it.

Cornwallis decreed that the first Ordnance Survey map would be of England’s most south-easterly county, Kent, one of the most vulnerable areas to French invasion. When the triangulation had begun in 1792, Mudge had initially bypassed Kent as William Roy had already plotted a series of triangles over that county during the Paris–Greenwich triangulation in 1787 and 1788. But in June 1795 Mudge began to remeasure Roy’s Kent triangles in the name of superior accuracy. He hopped in Roy’s shadow from Dover Castle to Ringswold Steeple, which sits on a sand hill between Deal and Ramsgate; to Mount Pleasant House, near Thanet; to the rising ground near Wingham; and to churches at Chislet and Upper Hardes. When Mudge went into Kent, he found that the Interior Survey that was under William Gardner’s directorship had already started work on fleshing out Roy’s initial triangles into maps. The gangly Isaac Dalby had assisted Roy during the Anglo-French collaboration and Mudge sent him to talk Gardner through the original rationale and methodology of Roy’s project.

The Interior Survey consisted of two activities. First Gardner devised a secondary triangulation to complement the principal triangulation and to create an accurate skeleton within which measurements of relatively small portions of land could be fitted. For the secondary triangulation of Kent, Gardner was presented with an eighteen-inch theodolite by Jesse Ramsden. This was a much smaller and more portable beast than the three-foot ‘Great Theodolite’ of the primary triangulation and it could be easily lifted to the roofs of high buildings. Then a small team of Tower draughtsmen – which in the 1790s included, among others, George Pink and Charles Budgen – filled in the primary and secondary triangulations with detailed surveys of the land that were conducted on the large scale of six inches to one mile. The triangulation was used as a framework to maintain the accuracy of these interior maps and to prevent errors from mounting up, but it was often possible to conduct these adjustments
after
the topographical maps had been completed. The Trigonometrical Survey and Interior Survey worked at
different
paces, and although it was helpful for the surveyors of the latter to base their maps on a finished triangulation, it was not absolutely essential.

To make their maps, the Interior Surveyors may have followed something similar to the ‘General Instructions for the Officers of Engineers Employed
in Surveying’ that Charles Lennox had set out in 1785. Lennox, and Roy too, had commanded their interior map-makers to use ‘small Theodolets and chains’ to ‘proceed around the Contours and Creeks of the shore; along the great Roads and lanes; and also along the course of the Rivers, and Rivulets. The Boundaries of Forests, Woods, Heaths, Commons or Morasses, are to be distinctly Surveyed,’ Lennox had emphasised, ‘and in the enclosed parts of the Country all the Hedges, and other Boundaries of Fields are to be carefully laid down.’ There is little documentary evidence that describes exactly how the Interior Surveyors mapped Kent, but it is likely that they measured the direction and lengths of the roads and rivers using a
perambulator
(or surveyor’s wheel) and compass, and recorded the results of these traverse surveys in fieldbooks. The road and river surveys were then drawn onto paper on which the primary and secondary triangulations were very lightly traced to fix their exact positions. Then, square mile by square mile, the Interior Surveyors gradually filled in the intervening details of this
skeleton
map, using theodolites to ascertain the bearings of various landmarks from the roads and rivers. It seems they did not use the tried and tested method of plane-table surveying.

Before long, the Interior Surveyors had created what were known as ‘fair plans’ of every part of the country. The resulting charts and sketches were often intricate, beautiful productions that were brought to life through a vivid vocabulary of colour. As was customary in eighteenth-century European military surveys, the map-makers delineated rivers and lakes in blue,
settlements
in red and main roads in ochre. Greens and browns identified pasture and arable land. They recreated hills through the technique of hachuring, in fine black ink. Some altitudes are noted in red. Created over half a century, 351 of these intricate drawings are now held in the British Library in London. They range from unfinished skeleton plans and black-and-white outline drawings to meticulous and complete surveys of irregular portions of the British landscape, and they vary wildly in quality, richness of detail and use of symbols. But, in the words of the historian of the Ordnance Survey Yolande Hodson, some are indisputably ‘works of art’.

The river Thames was one of the most vulnerable features of England’s geography and laid the nation’s centre of power open to naval invasion. So
the decision had been taken early on by Cornwallis to include the southern reaches of Essex alongside the whole of Kent on the Ordnance Survey’s first map. Its map-makers’ representation of the Thames estuary was indebted to information from Britain’s new Hydrographic Office. Six years prior to the publication of the Ordnance Survey’s Kent map, the Admiralty’s first Hydrographer, the Scottish geographer Alexander Dalrymple, had been appointed by George III. In 1800, the first Admiralty Chart, of Quiberon Bay in Brittany, had appeared. As the Ordnance Survey mapped Britain’s mainland, the Hydrographic Office was working its way around its coast. Both institutions helped to ensure the safety of this island nation in a period of prolonged turmoil. But it was relatively slow going. It took Gardner and his surveyors over three years to finish their maps of Kent ‘in a masterly manner’. By the final year of the eighteenth century, both the Trigonometrical and Interior Surveys of that county had been completed, and the compilation of these materials into a complete map was on the horizon.

 

I
N THE YEARS
immediately following the Interior Survey’s mapping of Kent, the Ordnance Survey’s personnel changed in important ways. In January 1798 the
Sun
newspaper reported: ‘Died, Last week in London, Colonel Edward Williams, of the Royal Regiment of Artillery, well known in conducting the Trigonometrical Survey of this Kingdom.’ Well known he may have been, but he had not been particularly well respected by his
cartographical
colleagues. Williams had made his indifference to the mapping project under his command clear when he had been invited to present the King with details of its progress in 1796. He had preferred to talk instead about the improvements he had made to Woolwich’s artillery stores and it was left to William Mudge to describe the Trigonometrical Survey’s
endeavours
and to present George III with another printed account of its progress.