Grids & Datums UNITED KINGDOM By Clifford J. Mugnier, C.P., C.M.S. gland and Scotland agreed to join as Great naissance in 1819. In 1824, Parliament or- “OS was founded in 1791 by Britain in 1707 and with Ireland in 1801. The dered Colby and most of his staff to Ireland, the Master General of Ordnance present name of Great Britain and Northern to produce a detailed six-inch to the mile [equivalent to the Minister of Ireland was adopted in 1927. The area of valuation survey. Colby designed specialist Defense today], Charles Lennox, Great Britain is slightly smaller than Oregon; measuring equipment, established system- the kingdom has a 12,429 km coastline and atic collection of place names, and reorga- Duke of Richmond. His Grace the lowest point is Fenland (-4 m), the high- nized the map-making process to produce had been an outspoken sup- est point is Ben Nevis (1,343 m). Great Brit- clear, accurate plans. But Colby the perfec- porter of the American colonists ain is only 35 km from France and is linked by tionist also traveled with his men, helped to in the House of Lords. In the “Chunnel.” Because of the heavily in- build camps, and arranged mountaintop feasts December 1775 he declared dented coastline, no location in the country with huge plum puddings at the end of each is more than 125 km from tidal waters! surveying season. that the resistance of the Thanks to the web site of the Ordnance “Soon after the first Irish maps began to colonists was “neither treason Survey, “England was squeezed between appear in the mid-1830s, the demands of nor rebellion, but it is perfectly rebellion in Scotland and war with France the Tithe Commutation Act provoked calls justifiable in every possible when King George II commissioned a mili- for similar six-inch surveys in England and tary survey of the Scottish highlands in 1746. Wales. The government prevaricated but, political and moral sense.” Yet The job fell to William Roy, a far-sighted by then, there was a new power in the land. less than 10 years later he was a young engineer who understood the strate- This was the era of railway mania and if the government minister – I think gic importance of accurate maps. Walk into one-inch map was unsuitable for calculating anywhere else in Europe he Ordnance Survey’s Southampton headquar- tithes, it was virtually useless for the new ters and you’ll see Roy’s name engraved on breed of railway engineers. To make matters would have been executed or the curved glass entrance doors, yet his vi- worse, mapping of England and Scotland re- exiled! He was succeeded as sion of a national military survey wasn’t mained incomplete and, in 1840, the Trea- Master General by Lord implemented until after his death in 1790. sury agreed that the remaining areas should Cornwallis, who didn’t appear By then Europe was in turmoil, and there be surveyed at the six-inch scale. Now, sur- were real fears that the French Revolution veyors needed greater access than ever be- to have suffered any long-term might sweep across political damage by that unfor- the English Channel. tunate incident at Yorktown. An Realizing the danger, Major General William Roy once wrote, “On early Director General of OS, the government or- one occasion he (Ramsden) attended at William Mudge, had served on dered its defense Buckingham Palace precisely as he supposed ministry – the Board Cornwallis’s staff in the southern of Ordnance – to be- at the time named in the Royal mandate. The colonies.” gin a survey of King remarked that he was punctual as to the — Russell Fox, Ordnance Survey England’s vulnerable day and hour, while late by a whole year!” southern coasts. In June 1791, the Board The United Kingdom includes England, Scot- purchased a huge new Ramsden theodolite, fore; and so, in 1841, the Ordnance Survey land, Wales, and Northern Ireland. The latter and surveyors began mapping southern Brit- Act gave them a legal right to ‘enter into was included in a previous column on the ain from a baseline that Roy himself had and upon any land’ for survey purposes. A entire island of Ireland (PE&RS, March 1999). measured several years earlier. few months later Ordnance Survey’s Evidence from pre-Roman times includes “The first one-inch map of Kent was pub- cramped Tower of London offices were at Neolithic mound-tombs and henge monu- lished in 1801, and a similar map of Essex the centre of a national catastrophe when ments as well as Bronze Age Beaker culture followed – just as Nelson’s victory at Trafalgar fire swept through the Grand Storehouse, tools, graves, and the famous Stonehenge made invasion less likely! Within twenty threatening to engulf the Crown Jewels in monument. Brythonic-speaking Celtic years about a third of England and Wales had the Martin Tower. Miraculously, the Jewels peoples arrived during migrations of the first been mapped at the one-inch scale. If that were saved, and most of Ordnance Survey’s millennium B.C., according to Webster’s seems slow in these days of aerial surveys records and instruments were also carried Geographical Dictionary. England has existed and global positioning, spare a thought for to safety. But the blaze highlighted the as a unified entity since the 10th century. Major Thomas Colby – later Ordnance Survey’s desperate need for more office The union between England and Wales was Survey’s longest serving Director General – space, and prompted a move to Southampton. begun in 1284 and formalized in 1536. En- who walked 586 miles in 22 days on a recon- “The scene was now set for two decades 1092 October 2003 PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING Grids & Datums of wrangling over scales. Throughout this now familiar concrete triangulation pillars mapping agency’s data now underpins up to period, Victorian reforming zeal was creat- on remote hilltops throughout Britain. Deep £136 billion-worth of economic activity in ing an acute need for accurate mapping. The foundations were dug by hand, and staff Britain – everything from crime-fighting and issue was settled piecemeal until, by 1863, dragged heavy loads of materials over iso- conservation to marketing and mobile scales of six inches and twenty-five inches lated terrain by lorry, packhorse and sheer phones.” to the mile had been approved for mountain brute force. The Davidson Committee’s final The original triangulation of Britain was and moorland, and rural areas respectively. report set Ordnance Survey on course for carried out between 1783 and 1853 and is The one-inch map was retained, and detailed the 21st century. The National Grid refer- known as the “Principal Triangulation.” Jesse plans at as much as ten feet to the mile ence system was introduced, using the metre Ramsden, a gifted but dilatory gentleman, were introduced for built-up areas. as its measurement. An experimental new built the theodolite where the overall size “By now, Major-General Sir Henry James 1:25,000 scale map was launched, leaving of the horizontal circle measured 3 feet in – perhaps Ordnance Survey’s most eccen- only the one-inch unscathed. It was almost diameter and was divided to a precision of a tric and egotistical Director General – was forty years before this popular map was su- tenth of an arc second! (That’s the same pre- midway through his twenty-one year term. perseded by the 1:50,000 scale series, first cision as the Wild Heerbrugg T-4 astronomi- James quickly saw how maps could be proposed by William Roy more than two cen- cal theodolite still manufactured as recently cheaply and quickly enlarged or reduced us- turies earlier. as the 1980s). Major General William Roy ing the new science of photography, and he “In 1939, war intervened once again. The once wrote, “On one occasion he (Ramsden) designed an elaborate glass studio at Royal Artillery was now responsible for its attended at Buckingham Palace precisely as Southampton for processing photographic own field surveys, but over a third of Ord- he supposed at the time named in the Royal plates. James planted his name on every- nance Survey’s civilian staff were called up, mandate. The King remarked that he was thing he touched, and later claimed to have and its printing presses were kept busy with punctual as to the day and hour, while late invented photo zincography, a photographic war production. It wasn’t a soft option. En- by a whole year!” The genius responsible for method of producing printing plates. In fact, emy bombing devastated Southampton in the final adjustment and computation of the the process had been developed by two of November 1940 and destroyed most of Ord- Principal Triangulation of 1783-1853 was his staff. By 1895 the twenty-five inch sur- nance Survey’s city centre offices. Staff were Colonel Alexander Ross Clarke who also vey was complete. dispersed to other buildings, and to tempo- computed the Clarke ellipsoids of 1858, 1866, “The twentieth century brought cyclists rary accommodation at Chessington. But the and 1880. The network selected by Clarke and motorists swarming onto the roads, and military appetite remained insatiable – the was an interlocking system of well-condi- the new Director General, Colonel Charles Normandy landings alone devoured 120 mil- tioned triangles. In 1967, the Ordnance Sur- Close, prepared to exploit this expanding lion maps! vey wrote, “This network was geometrically leisure market. But by now, the tide of his- “After the war, Ordnance Survey returned of great strength since it involved no fewer tory was sweeping Ordnance Survey back to Davidson’s agenda; the retriangulation was than 920 condition equations to find correc- to its roots.