Celebrating William Mudge: Creator of the first Ordnance Survey map

Portrait of William Mudge painted by James Northcote (assistant to Joshua Reynolds) in 1804 (copyright Ordnance Survey) Archant

April sees the bicentenary of the death of William Mudge, the brilliant soldier turned surveyor responsible for the first map to be produced by the Ordnance Survey – and it was of Kent

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Two hundred years ago, on 16 April 1820, William Mudge died. Not a name that resonates like those of some of his contemporaries – Byron, Wordsworth, Darwin – but one that should be better known for he literally put Kent, and much of Britain, on the map.

Since 1518 map making in Britain had been a minor responsibility of the ‘Board of Ordnance’, an independent military body which operated from the Tower of London.

There a talented small band of military and civilian draughtsmen, some as young as 11, busied themselves with the intricacies of military surveying, trigonometry and geometry, all fundamental for map making.

Towards the end of the 18th century growing concern about the prospect of a French invasion of England focused the minds of politicians on the fact that available maps of the south coast didn’t provide details of features that could hide soldiers, where troops could be quartered or the nature of terrain over which they might have to fight.

With national security at stake, the need for a countrywide survey to produce detailed, accurate maps had become urgent. It was clearly a job for the Board of Ordnance: the skills of the map-makers were going to be much in demand.

Among them was 28-year-old Lieutenant William Mudge, a man who was to play a seminal role in the United Kingdom’s map-making history.

To get to know the man we must first go back to 1 December 1762 when he was born in Plymouth. At a time when who more than what you knew mattered, William was fortunate to be born into what is on record as being ‘an extraordinary conglomeration of high achievers with a wide variety of interests, temperaments and friends’.

A copy of the 1801 map of Kent, the first map to be produced by the Ordnance Survey (copyright Ordnance Survey) A copy of the 1801 map of Kent, the first map to be produced by the Ordnance Survey (copyright Ordnance Survey)

Little is known about William’s early schooling, but when only 15 years old he was accepted into the prestigious Royal Military Academy at Woolwich to train as a commissioned army officer.

Graduating two years later with the rank of second lieutenant, he was posted to South Carolina to join the British army fighting in the American War of Independence.

He returned to England in 1783 and was stationed in the Tower of London, where he was given the opportunity to study higher mathematics.

With his good social contacts and considerable mathematical talent it is not surprising that in July 1791 William was appointed Deputy Director of the new survey under the Director, Major Edward Williams.

The soldier becomes a surveyor

Land surveying methods had progressed considerably following the invention in 1787 of the first theodolite, an instrument used to measure horizontal and vertical angles.

In 1784 William Roy, a Scottish surveyor, had been commissioned by the Royal Society to solve the dispute over the relative positions of the Royal Observatories of Greenwich and Paris.

The work had involved the accurate measurement of a baseline on the level ground of Hounslow Heath (now occupied by Heathrow Airport), followed by ‘triangulation’, a method for finding the position of a feature in the countryside by forming triangles from known points.

Roy’s survey data would provide a useful start for the British Survey.

Wasting no time, during July 1791 Williams and Mudge started carefully re-measuring the 5.2-mile long Hounslow baseline. It took 11 weeks and finally identified an over measurement of only 4.6 inches.

The triangulation began in the spring of 1792: it was work for young men. Regardless of the weather they had to haul the theodolite, weighing 90 kilos, on a horse-drawn cart along often mud-choked roads and, at every observation point, winch it by crane to the top of a 30-foot high wooden tower then, when possible, accurately read angles of sight to distant landmarks.

The surveyors sent all the measurement data in stages to the Tower of London, where draughtsmen converted them into maps. On 1 January 1801 the first map – an ‘Entirely New & Accurate Survey of the County of Kent’ – was published at a scale of one inch to the mile.

An Austrian general pronounced it ‘the finest piece of topography in Europe’

Mudge makes his mark

William was appointed Director of the survey in 1798 after the death of Edward Williams. Added to the increased responsibilities were family worries. In the late 1780s he had married Jane Williamson, the daughter of a superior officer, and by 1800 they had five children. With William’s work keeping him away from London much of the year, his family had lived in Devon so he had seen little of them.

The work was relentless. In 1802, recognising that he needed extra help, William recruited a wiry 17-year old Thomas Colby into the surveying team. Thomas proved to be a huge asset, assisting William with surveys as they extended into northern England, Wales and Scotland.

William’s work didn’t go unnoticed. In 1798 he was elected a Fellow of the Royal Society, in 1809 he was appointed Lieutenant-Governor of the Royal Military Academy at Woolwich, in 1813 he was promoted to the rank of Regimental Colonel and in 1817 awarded an honorary doctorate by the University of Edinburgh.

Following the recruitment of Thomas Colby, William was able to spend more time in London, which gave him an opportunity to buy his first house. It took him three years to find a suitable place, but in 1808 he bought one near to Oxford Circus and settled his wife and children in it.

It was to here that William retreated in March 1780, severely unwell with ‘internal inflammation.’ Sadly, he died shortly afterwards at the relatively young age of 58.

And the Ordnance Survey?

It blossomed to become today a UK government-owned limited company with prestigious headquarters in Southampton and a map-making reputation that is second to none.

Map of a Nation

Map of a Nation, by Rachel Hewitt is published by Granta Books and tells the story of the creation of the Ordnance Survey map – the first complete, accurate, affordable map of the British Isles. www.ordnancesurvey.co.uk