The birth of Ordnance Survey’s mapping

Cassini Old Series: first published 1805 to 1874

In 1747, a Scottish surveyor by the name of William Roy had an idea.

This was by no means the first good idea that came from Scotland – the long list of Scottish inventions includes (in no particular order) television, bicycles, steam engines, golf, telephones, adhesive postage stamps, international time zones, tarmac, passenger steamboats, pneumatic tyres, the Encyclopædia Britannica, the Bank of England, gas lighting, ultrasound scans, postcards, the decimal point, lime cordial, colour photography, Penicillin, Bovril, lawnmowers, logarithms, mackintoshes, marmalade, refrigerators, radar and Dolly the cloned sheep. What was different about Roy’s idea was that it wouldn’t become reality for over half a century, and only then because of a Corsican soldier.

Roy had been detailed to create accurate maps of Scotland in the aftermath of Bonnie Prince Charlie’s rebellion in 1745. Roy saw this as an opportunity to execute a complete survey of Britain such as was then becoming commonplace elsewhere in Europe. Repeated lobbying of the government failed to extract the necessary funds. He did at least have the satisfaction of measuring the base-line between Hampton and Hounslow Heath in 1784, which became the starting point for all subsequent surveys. He died in 1790, his dream still unachieved.

By then, however, forces were at work which were to make a proper survey a priority. The threat of invasion by Napoleon’s armies was becoming ever more real and civil defence needed to be stepped up. To its horror, the government discovered that the only complete set of maps of the country relied on Tudor cartography and were wholly useless. Something had to be done.

Detailed plans of Plymouth and other points on the south cast had been made during the 1780s and early 1790s at the behest of the Duke of Richmond, the Master-General of the Ordnance and a supporter of Roy’s ideas. This helped convince the government that the task was viable. The original plan was to produce detailed maps of the vulnerable southern coastal regions; and into this task the surveyors of the Board of Ordnance threw themselves with military zeal.

The combination of hard labour and painstaking technical detail involved in the work was staggering. The surveyors had to transport heavy and delicate instruments on poor roads, in all weathers and (of course) without accurate maps to guide them. The driving force behind this was the indefatigable Thomas Colby, who later became Superintendent of the Ordnance Survey in 1820. Colby designed many of the instruments used in the surveys and did much to standardise the processes of collecting the data and creating the final maps.

The scale chosen was an inch to the mile (1:63,360). Various, partially experimental, maps of Sussex and Kent were published between 1795 and 1801, with the first fully Ordnance Survey sheets (of Essex) appearing in 1805. Sheets covering the West Country (which was also identified as a possible invasion point) were appearing by 1809. The maps were regarded as being so vital to national security that during the Napoleonic Wars an embargo was placed on their sale to the public.

In fact, this invasion did not materialise; but by then the survey had turned into a massive national project on a scale not attempted since the Domesday Book in the 1080s. The full survey of England, Wales and the Isle of Man was not to be completed until 1874, the resulting maps later becoming known as the Old Series. Roy’s dream had, with the help of a Corsican soldier, finally been realised.

The mapping used the Cassini projection, which was to be that most commonly employed by the Ordnance Survey until the 1940s. It soon became clear that the policy of using a meridian of 3ºW for the western maps and Greenwich’s 0º for the eastern ones would lead to a convergence between the western and eastern sheets which became more pronounced as the maps progressed north. It was eventually decided to use a single new meridian with its origin in Delamere Forest in Cheshire.

This was but one of many refinements that the Ordnance Survey made, on the hoof, to the way the maps were produced. Map legends, an essential part of modern cartography, were not originally used. The Old Series legends used here have been created with the invaluable help of cartographic scholars (in particular Dr Richard Oliver) and reflect only the symbols that were consistent across the series’ long gestation. Many features, such as prehistoric sites, were not originally considered worthy of inclusion on the early maps, produced for military purposes: later, as they acquired a more civilian aspect, these began to be included.

An even greater problem was caused by the rapid changes which, co-incidentally, were overtaking the country at just the time the Old Series maps were being created. No aspect of this development caused as many changes to the landscape, and an many problems for Ordnance Survey, than the arrival of the railways. As the full impact of this revolution was only clear by the later part of the 19th century, this has been considered in more detail in the article covering the Revised New Series.

One aspect of the explosive growth of the railway network did, however, have an impact on the Old Series maps. As the railway navies were working more quickly than the surveyors, many maps almost immediately became out of date. Due to the limitations of printing technology and the sheer volume of work the whole project entailed, the solution was to re-issue many sheets with railways or other major changes over-engraved but without any revision of other features. As these new sheets still bore the original publication date it is often hard, and at times impossible, to date the revisions. From the 1850s this problem was largely solved by more flexible printing methods and by the fact that Ordnance Survey in their northward progress was in general surveying areas that already had railways and so included them from the outset.

These Old Series maps provide a fascinating record of the landscape on the eve of a dramatic demographic and social change. Many of today’s large cities were well established, but had yet to begun their spectacular encroachment into the surrounding villages. In general, though, the landscape was much as it had been for hundreds of years, with farms, villages and small market towns surrounded by fields, woods and open countryside. These maps perfectly capture a nation on the cusp of transition; faithfully recording, almost by chance, the final generations of a centuries-old agrarian society before its headlong rush towards urbanisation.

The navvies & the surveyors

Cassini Revised New Series (in Colour): first published 1896 to 1904

One of the world’s greatest transport revolutions started with a wager in a west country village.

In the first years of the 19th century Richard Trevithick, a Cornish engineer, bet a friend that he could build and successfully operate a steam locomotive running on rails. Trevithick won the wager, accomplishing this seemingly impossible feat in February 1804. He was unable to capitalise on this achievement, however, and it was left to others, notably George Stephenson, to refine and develop this new technology over the next 20 years.

As it happened, the mapping of the country had begun at about the same time. If another bet had then been taken as to which would happen more quickly, the creation of a paper landscape or a transport network of iron rails spanning the length and breadth of the land, most of the smart money would have been on the cartographers. They, after all, only had to measure: the navvies had to build.

In fact, the navvies won hands down. Whereas the work of the Ordnance Survey was government-sponsored and without rivals, the railways were anything but. Labour was plentiful, technology was ready and large profits awaited the winners. The scale of railway building in the middle of the 19th century outstripped, in both in its speed and its impact, any transport development in Britain’s history.

About 100 miles of track existed in 1830; this had grown to 1,500 miles by 1840, and to 10,400 miles by 1860. The effect on the areas through which the railways passed was often dramatic, particularly around large junctions and termini: an estimated 4,000 houses, for example, were demolished during the building of St Pancreas station in London. This revolution helped drive Britain’s increasing prosperity and industrialisation during the rest of the century, and contributed to numerous social changes including the growth of trade unionism, the advent of tourism and the standardisation of national time.

The railways also enabled goods and people to be quickly transported to and from large towns and cities, so hastening the existing trend towards urbanisation. In 1800, around 75% of the population had lived in the countryside and the rest in the towns; by 1880, these proportions had been reversed. As a result, many long-familiar aspects of the landscape were changing for good – and changing far more quickly than they could be mapped.

The original (Old Series) maps were still being produced by the time the railway boom reach its peak in the early 1850s. As the surveyors were methodically working their way up from the south coast, railways are absent from the southern sheets but start to appear in the midlands and are everywhere in the north. This result was far from ideal for a national mapping agency that prided itself on accuracy. For some time, Ordnance Survey engraved new railway lines on the old plates, but this failed to reflect other changes such as the growth of towns, many of which were caused by the railways.

It was a bitter irony. At many times in the late 18th century the government had had both the means and the talent to conduct a national survey and catch up with their European neighbours. At any time then (or indeed at any time before then) the landscape would, during the 70-odd years required for the operation, have remained largely unchanged. The very time they eventually got down to it, however, was when the revolution of the railways was about to make maps go out of date almost before the ink was dry on the sheets.

Once started, such a project must continue for as long as there is change to record. Even without the railways, change was happening. The maps were increasingly used by civilians, as well as by the soldiers whose needs were the initial impetus for their creation. As a result, each revision of the maps needed to show, as well as new features, pre-existing features which either had not previously been recorded (such as ancient monuments) or which now needed to be described in ways which technology now permitted, or users now demanded (such as contour lines and colour). There was also the eternal tension between Ordnance Survey, the military, the Treasury and, increasingly, the public as to who was going to pay for all this. For the rest of Ordnance Survey’s history, these conflicting demands would dominate many of the discussions about revisions and new surveys.

This process began in the 1840s, from when surveys were carried out at increasingly detailed scales and were used for many purposes including railway construction, geological survey and sanitary reform. In order to ensure complete and accurate coverage, the 1841 Survey Act had already given surveyors the right to ‘enter into and upon any land’ in the course of their duties. Having moved into new premises in Southampton after a fire in 1841 had destroyed their overcrowded Tower of London headquarters, the Ordnance Survey, armed with its new powers and instructions, began work on re-surveying the country. The results, published at the one-inch scale between 1876 and 1896, were later to be known as the New Series.

In 1893 a more thorough revision was undertaken which resulted in the publication of 346 sheets, between 1895 and 1899, of what became known as the Revised New Series (later sheets were merely the same with hachured hills added). Improvements in reproduction and printing techniques helped these to be even clearer and more accurate than their predecessors.

The railways were a transport revolution: in the late 19th century another technological development had emerged. This was colour printing. Though in no way as cheap, accurate or simple to execute as that we take for granted today, it none the less revolutionised graphic art, including map production.

The military soon started pressing for Ordnance Survey to produce a national mapping series in colour. Financial, technical, aesthetic and political considerations as to how this could best be accomplished were hotly debated between the numerous interested parties. In late 1896, the Ordnance Survey concluded that sales of the new maps to civilians would help subsidise the costs, a consideration which helped drive forward production of the first colour one-inch map the following year. Even then, the debate continued, and some features, such as the use of green for woodland (which only appeared on the northern sheets), were amended as the series progressed.

Although the final results were something of a compromise between the often incompatible aims of the military, the Treasury and the Ordnance Survey, the Revised New Series in colour stands as an elegant portrait of late-Victorian Britain. As the first coloured one-inch map series, it was also the precursor of Ordnance Survey’s 20th-century mapping which, from the Popular Edition onwards, would be increasingly determined by the demands not of the military but rather of the civilian market.

The Revised New Series captures Britain at the height of its late-Victorian imperial prosperity. All but the very largest cities still had clearly defined boundaries, but with little of the urban sprawl that has since overtaken so much of the landscape. The construction of over 16,000 miles of railway track (of which about half survives today) had made its mark on the physical landscape, both by its very presence and through the social mobility that it helped encourage. Alongside and, increasingly, beneath these new developments, the maps still clearly show many of Britain’s more ancient features and settlements: but these are now dominated by the new Victorian urban society which in many ways forms the basis of our own.

Maps, motor cars & all that jazz

Cassini Popular Edition: first published 1921 to 1926

The 1920s is a decade that continues to fascinate. Penicillin, art deco, modernism, regular trans-Atlantic travel, women’s suffrage, talking pictures and the popularisation of jazz all date from this decade; as do the General Strike, the Great Depression, The Irish Civil War, the birth of the Soviet Union and the publication of Hitler’s Mein Kampf. Sandwiched between two world wars and existing on the edge of today’s living memory, the ‘Roaring Twenties’ has achieved an iconic status that few other ages of the 20th century, the 1960s apart, can match. Both decades have more than a whiff of frivolity, hedonism and excess; both witnessed the social emancipation of the young through music and fashion; both were periods of great cultural change. Above all, both appear glamorous in retrospect, bursting with creative energy and made hectically alive with the shock of the new.

The 20s’ world of jazz, cocktails and ocean liners was one side of the picture (and one which only a small percentage of Britons would have experienced first-hand) but there were also more profound and wide-spread forces at work. The decade arguably saw the emergence of ‘modern’ Britain, with many aspects of life that had been established for as long as anyone could remember, such as the dominance of the railways, colonialism and the power of the aristocracy, soon to be swept away for good. By slow degrees, British society was becoming more equal. Practical signs of this change included shorter working hours and more paid holidays which were fuelling a desire for leisure and recreation, and thus in turn for travel.

Every so often a technological development occurs which revolutionises the world, for better or worse. Fire, the wheel, printing, gunpowder, Arabic numerals and, more recently, steam engines, telephones, airplanes, cathode-ray tubes and silicon chips would all find a place on such a list. So would the motor car. In 1909, 53,000 cars were registered in Britain; twenty years later there were over a million. Many who could not afford (or did not dare) to use a car cycled instead. Britain had over 280,000 miles of road on the eve of the First War and although these were not of a consistent quality, they were fast being improved.

For the first time, the train companies – which had, since the 1830s, provided the pre-eminent method of transport – were faced with a real competitor, particularly given the emergence of a fledgling tourist industry. Every effort was made to attract these travellers, and the posters and publicity material produced at this time by resorts and transport bodies rank amongst the finest achievements of British graphic art. More people were travelling than ever before – and all of them, particularly the motorists, needed maps.

Responding to this, the Ordnance Survey, under the Director-Generalship of Colonel Charles Close, began re-surveying the country in 1912. After the war, and guided by the results of public consultation and backed up with a powerful marketing campaign, the one-inch Popular Edition was launched. Its iconic cover of a cyclist sitting on a hillside studying a map is an image which for many defines the supposed peace and innocence of the decade.

The maps were based on the third national revision (published in the first decade of the century) but with an altered colour scheme using seven plates. Roads, for instance, were now coloured according to their suitability or otherwise for motor traffic. The first maps were published in 1919 and the series was completed seven years later. For the first time, contour lines were used in place of artistic hachures. These were, as well as being more accurate, less obtrusive. This change was necessary because of the increasing number of features that now needed to displayed. A side effect was to make the landscape appear flatter than previously, an illusion that the increasing number of motorists or bus travelers would also have shared.

The Popular Edition captures the ever-changing landscape of Britain at a crucial time in its history. The inter-war years arguably saw the emergence of ‘modern’ Britain. The patterns of development and transport links these maps reveal are in many cases familiar to the contemporary eye. Much, however, was about to change, in particular the suburban encroachment into the countryside and the further expansion of the road network. The Popular Edition is a potent record of the Britain that was about to be traded for the motor car. By an irony, it also provided the British with their first motoring maps.

The post-war landscape

Cassini New Popular Edition: first published 1945 to 1948

The mid 1940s was at period of intense and often painful regeneration and renewal in Britain. The Second World War had been won, but at a vast financial and human cost. The physical damage and disruption, though less severe than in many other countries, was considerable: more insidious were the conflict’s legacy of social and geo-political changes. Atlee’s post-war government promised a new society forged from the wreckage of the old, although the immediate reality was one of bomb sites, creaking infrastructure and continued food rationing. The country’s post-imperial decline was already a fact in 1945, even though this would not become clear until the Suez crisis a decade later.

The war had proved the importance of the railways in moving vast numbers of troops and evacuees, but it was to be their last great contribution to the nation’s transport needs. The network had survived the conflict without significant damage, but this proved to be a mixed blessing as investment, which was badly needed after years of neglect, was thus not seen as a priority.

One major change was the nationalisation of the four railway companies in 1947. A brief period of recovery followed, but from the early 1950s passenger numbers started a decline that was not reversed until the late 1970s. The car had taken over as the transport method of choice. Over 2.4 million vehicles were registered in Britain by the end of the 1940s as opposed to about a quarter of a million in 1921. Car travel increased social as well as personal mobility and also led to an increasing demand for accurate mapping.

The problem of surveying and recording Britain’s ever changing landscape – one inhabited by over 50 million people by 1951 – had been exercising the minds of the government, the military and the Ordnance Survey ever since the completion of the Popular Edition in the late 1920s, although the cartographic ambitions of these parties did not always co-incide. The Fifth Series of the 1930s was the result of various experiments of projection, sheet-lines, metric grid and styling which ultimately proved unsuccessful and the project was abandoned in 1938 with only a small number of sheets having been produced.

Despite, and in some cases because of, the demands of the war, a new series was required. This became known as the New Popular Edition, which first went on sale (as ‘provisional’ sheets) in 1943; was published formally between 1945 and 1948; and which was eventually superseded by the Seventh Series in the 1950s.

The New Popular Edition was in many ways a departure from previous Ordnance Survey series. Although still produced at the one-inch scale, it included (as recommended by the Davidson Committee is 1938) a metric grid. It was also the first series to incorporate Scotland as well as England and Wales using a consistent numbering system, and was the first to be produced in portrait rather than squared or landscape format, with sheets of 45km x 40km. It also used the Transverse Mercator projection rather than the Cassini which had been used by Ordnance Survey since the later sheets of the Old Series almost a century before.

The New Popular Edition was not produced from any one revision designed for the creation of the series and so is something of a hybrid: cartographically a stepping stone between the iconic popular Edition of the 1920s and the Seventh Series of the 1950s and the metric-scale 1:50,000 maps that followed from it. The sheets used of the major cities were based on a full revision in the 1930s with further revisions in 1938. These were then ‘road revised’ in 1946, an exercise which also included recording other features including wartime bomb damage. They thus provide a poignant record of the immediate aftermath of the conflict: the ‘raw material’ which planners and developers in subsequent decades used, for better or worse, to create the Britain that we know today.

Mapping today’s Britain

Ordnance Survey’s present-day 1:50,000 maps

The current Ordnance Survey 1:50 000 mapping (represented, in most peoples’ minds, by the Landranger® series) had its origins in the inter-war years. The Davidson Committee which sat between 1935 and 1938, recommended, in its 1938 report, a radical overhaul of the organisation’s mapping, including a re-triangulation of the entire country. This Herculean task was driven forward by the energies of Major-General Malcolm MacLeod, the latest in a long succession of dynamic Directors-General.

The outbreak of hostilities in 1939, however, diverted expertise and resources elsewhere – 120 million maps were printed for D-Day alone – and in the immediate post-war years the one-inch New Popular Edition (or Sixth Series), and then the Seventh Series, were produced to replace the Popular Edition. The re-triangulation was completed only in 1952 and it was not until the 1960s, after the Ordnance Survey had moved from its temporary HQ at Chessington into its new home on the outskirts of Southampton, that it was able to attempt the task of producing the new series of maps envisaged by the Davidson Committee forty years earlier.

The metric grid had been introduced on the one-inch New Popular Edition (of which some sheets were printed up to 1941 but – echoing restrictions placed upon the British public during the later Napoleonic Wars – were not for civilian sale), but it was not until the 1970s that a metric scale was introduced for the maps themselves. After several trials and false starts, 1:50,000 was eventually chosen. This represented an enlargement as compared to the long-established one inch to the mile (1:63 360) scale: necessary in view of the wealth of additional features that the increasingly crowded landscape contained and the variety of uses to which the Ordnance Survey’s maps were now being put. The country was divided into 204 sheets, each measuring 40km by 40km and many revisions to the style and use of colour were implemented.

The principal result was the now famous Landranger® series, the First Series of which – being but photographically-enlarged one-inch Seventh Series sheets – was published between 1974 and 1976: a span of two years, as opposed to the 69 years which had elapsed between the first and last one-inch Old Series sheets. These maps have stood the test of time, their Second Series issue – which were newly-drawn for 1:50 000-scale reproduction – being completed by 1988. They remain the definitive survey of the country, following a tradition that dates back over 200 years. Features as diverse as shopping centres and disused railways, car parks and stone monuments, rock screes and picnic sites are all included.

Computers, on-line or otherwise, have played an increasingly important role in the production of the Ordnance Survey’s maps ever since the nascent technology was used to help create the quarter-inch gazetteer in 1969. The Ordnance Survey had created digital versions of all its maps by 1995 and these are now available in an increasingly wide range of formats. The Serpell Committee recommended in 1979 that the Ordnance Survey become more ‘market led’, providing mapping to customers ‘in forms acceptable to them’, and there is currently an ever-expanding, and increasingly permissive, programme of partnership and other arrangements with third parties which enable Ordnance Survey’s considerable resources to be reproduced in numerous different ways.

As the UK’s only official mapping agency, Ordnance Survey has long occupied a unique and privileged position in national life. Recent years have, however, witnessed major changes in the way Ordnance Survey operates. The combination of a number of factors including the growth of the internet, increased public demand for digital mapping and governmental policy which increasingly supported liberalisation of information culminated, on 1 April 2010, in the launch of OS OpenData. This, in Ordnance Survey’s words, created ‘an online portal providing free and unrestricted access to a large range of mapping and geographic information.’ Since then, other relaxations of cartographic licensing have enabled third-party companies to provide mapping in increasingly innovative ways, so finally achieving the aims of the Serpell Committee’s report some 30 years earlier. Since early 2011, Ordnance Survey has been managing its new responsibilities from smaller, purpose-built premises in its historical south-coast home of Southampton.

What further changes Ordnance Survey and its mapping will embrace in the years to come is open to debate: what seems certain is that its cartography will continue to provide ever more fascinating comparisons with the landscapes of the past which it has so faithfully recorded for over two hundred years.