Ordnance Survey – Historical Notes

The First OS Maps:

The first Trigonometrical Survey was in 1791; beginning, near modern Heathrow Airport, on Hounslow Heath- so Surrey, Berkshire and Middlesex may well have been some of the earliest surveyed regions. In 1784 General William Roy measures out that first baseline of what would become the Ordnance Survey. It ran across Hounslow Heath, passing through Feltham. General Roy is commemorated locally in the name of a public house. The Ministry of Defence Geographic Centre still has a base in Feltham, used as a government mapping office.

Maps were drawn then engraved for publication. The early presses were in the Tower of London. The first plates were engraved copper – cold cut with a burin. A burin being the engraver’s cutting tool. Electrotypes were introduced in about 1850, as the copper plates began to wear out. Colonel Mudge was the first Director of the Ordnance Survey. Benjamin Baker was the first printmaker. Mudge was charged with map making for military purposes and Kent was the county of most concern; it was later, under Colby his successor, that the idea of rolling the Survey out from Kent northwards to cover the  whole country came about. In 1863 the sale of the maps was made more commercial; James Gardner managed the operation from 163 Regent Street London. The printer at that time was Mr Ramshaw. Railways first appeared in 1842, so it is possible to find maps or copies of them with railways before electrotyping- but generally the two phenomena came in together. Dr Harley noted that “No copy of a pre-electrotype maps with railways has actually been located” – they are a kind of Holy Grail of O.S. mapping. From 1882 onwards revision became more frequent as new towns, railways and features burgeoned. The First Series Ordnanec Survey was finished in 1873 and the last map of the series was that of the Isle of Man. The maps were not then  intended for popular use and one sheet cost the equivalent of two day’s average wages. The print runs of the 1st series were modest: never more than 1,000. It was this that gave an opening for Bartholomew to popularise the Survey with 1/2 inch Reduced Ordnance Surveys. They were forced to change their title to “Half in Reduced Survey” in 1911 when the Copyright Act was reinforced.


Ist Series OS maps showed railways on the revised electrotyped plates introduced from the 1850s onwards. Railway Companies are un named from Serioes 7 onwards- that is: from the 1950s; before that date, railway companies were named by their lines – LMSR, LNER, GWR, Southern Railway etc.. After that date- the network became British Railways and no name was necessary. Pre and Post World War 2 maps give the regional railway companies, and name individual lines.

Railway closures can, be old- several closed prior to the 2nd World War, a few earlier in the century. The manner for mapping closed and closing railways seems to have be:

1. Open; 2. Open but not public carriage; 3.Track marked stations in White; 4. Track bed marked in dashed line, cuttings shown, stations omitted; 5. Cuttings only as geographical features. 5. Much later, Pathfinder 2 1/2” maps show “track of old railway” as a green-way when it had become a leisure feature of the landscape.

Closed stations are marked white, open stations are red. A closed series of stations does not prove a closed line which might be open for freight traffic only, or passenger traffic which now by-passes these old halts. War time maps seem sometimes to show stations closed for the duration which were re-opened after the War.


Disused canals are similarly marked as disused, dry canal beds, and later just remnant bridges and surviving reaches. Unlike railways, the canal network has seen its closures being slowly reversed- a recent example is the Wey and Aran Navigation.


Civilian OS tends to use red for major roads, where as Military maps tended to use ochre- a major aesthetic difference. Interestingly, even on earlier maps, where all references are in miles, the grid is not Imperial but Metric. The Kilometre square seems to be much earlier in OS surveying than in popular use. Indeed there is no popular use of the Kilometre as an English land measure- but it is probably that the survey never used anything else in the 20th century. For example on a 1959 sheet one finds a kilometre measure, a mile measure, a kilometre grid but all references of distance where routes leave the map edge are in miles. The trend towards citing metric distance was reversed in the later Pathfinder series, it was part of a general socio-political change in which enthusiasm for ever closer European standardisation ebbed and the impetus to change popular usage was halted .

There seems to have been a major aesthetic change in the 1960 Survey when the detail on the maps was simplified and drawn in a bolder manner. Prior to that, civilian OS and military OS were generally similar, though the gridding methods were different. The Civilian Map Grid was Black not Purple or Blue. The Military field sheet-map was almost always smaller than the Civilian one, and used non-standard colours and paper- because many printers were co opted for the War time work.


It has been alleged that OS add deliberate errors to maps to guard against copyright infringement- and it is fun to try to spot these- if they exist. War time maps exclude sites of military significance, Airbases were usually redacted but Army camps were generally not. Naval Ports were left blank and white. One local 1 inch war sheets, churches were unmarked as were other important buildings which might have been useful to an enemy for navigation. Perhaps barracks and camps were unamended because they dated from the Pre war period and would have been readily available to an enemy from older maps. Airfield were a different matter.


The following were listed in a 1908 O.S. cover as being the published maps of the time:

Town maps on a scale of ten feet or five feet to a mile; General Cadastral Map on a scale of 1/2500 or 25 inches to the mile; General map on a scale of 6 inches to the mile; General map on the scale of one mile to an inch; .General map on the scale of two miles to an Inch; General map on the scale of four miles to an inch; General Map of the United Kingdom 1/1000000 or 16 miles to an inch; The 10ft, 5 ft and 6 inch maps are black only; A full sheet is 36” X 24”, a ¼ sheet is 18” x 12”; The 1, 4, & 10 mile maps are published in black also; Contours are on 1 and 2 mile maps; Special maps of certain districts are published; All small scale maps can be had, mounted on linen, unmounted, flat, folded in covers, or cut into sections and mounted on linen; Geographical maps are 6inch to the mile or 1 mile to an inch or 4 miles to an inch.”


SERIES 3 – one inch

The 1 inch  Contoured Road maps had a pictorial cover, often on a brick red ground with black and fawn designs with the borders. The artist most seen was Ellis Martin and he worked in either pen and ink or woodblock on scenes of travellers by car or cycle. He signs EM at the bottom corner of the early 1920s design, and his full name on the 1930s version. The Full Survey dates for these maps up until 1930s was often surprisingly early : 1870s +. The format was 7” by 4 1/2” folded and the maps were often dissected, though OS used the term “mounted in sections”. Such were the economics of the time that a price could be printed on the map cover. Integral pricing lasted until Series 7, by which time appliqué labels to alter printed prices were common. A contoured road map of 1919 in dissected form was 3/6d. Its covers were in concertina form. The grid was 2” and numbered west to east and lettered south to north. The numbers and letters named the squares of the grid not the lines of it. Each grid block was of 4 square miles. Road were unnamed and railways showed their company names. The ½ inch series used an olive green cover instead of Brick Red. Ellis Martin illustrated these too- His most famous 1” design showed a tweed-clad cyclist studying his map with a pipe in his mouth; his 1/2” touring map design was of an open topped Rolls Royce like car with 3 passengers and a driver.

A map found from this series had the following interesting characteristics: Intaglio blue printing for the hydrography, intaglio brown printing for the uplands, intaglio Black line printing for the roads and towns and names, red contours like a Belgian Institute Cartographique Militaire map, which it resembled in several characteristics. It had litho printed green for woods and litho printed orange for roads. Windmills, workhouses and smithies were marked throughout; thus there was an supposition that horse drawn carriages would be the normal form of conveyance. Hydrography at sea had contours marked in feet not fathoms and a very fine coastal hydrographic shading used parallel blue engraved lines which converged towards the coast line, to shade the coastal waters darker. The railways named older pre regional companies – LB&SCR in this case. It was linen backed and the sheet was about 30 inches by 20 inches between floating white linen covered boards- a most attractive but rarely seen series. (Map described was No. 137- Brighton Lewes Eastbourne).


Ellis Martin was the first professional cover artist employed by the Ordnance Survey. The purpose was to popularise the maps, the effect was startling. The highest ever map sales were achieved in the year 1921 and Ellis Martin’s colourful covers were largely responsible. Usually set within a red brown cover and an elaborate festooned leaf border; the Royal Arms crowned the image. The picture by Ellis Martin- showed a man in Tweed Cap, pipe in mouth, and cycling gaiters, sat on sloping grass studying a map from a hill-side with his bicycle propped to his right- In front of him is a generic idealised English landscape.  In the distance is a bay and cliffs. In the middle distance a viaduct crosses a river and hills descend to its valley. At the base of the hill woodland frames the image. The artist signs the 1920s covers “EM” at bottom right. One would guess from the mark making that the original was an ink drawing rather than woodblock. Of the Popular Edition of 1919-1921 Nicholas Crane, historian and broadcaster noted” This represents the last view of Britain before it was over-run” (by the motorcar) Timeshift, BBC Sept 2015.

Series 5 – 1 inch

Generally, these have a blue cover and on them the famous Ellis Martin cover is updated to show a man of the 1930s- the cycle is gone as is the hat, and the Tweed jacket. His hair is in the short sided manner of the 1930s. He still smokes his pipe but now has a short sleeved cardigan, a shirt with sleeves rolled up and a ruck sack on his back- The cyclist has become a hiker. Otherwise the landscape of the image is unchanged, as is the rest of the cover lay out. The artist signs these 1930s covers “Ellis Martin”. Series 5 maps are often of more localised areas than Series 4. They are seldom seen; perhaps their production was quickly compromised and curtailed by the outbreak of war. The implication here is that the golden age of cycle touring is over- This man may be a car driver- his exploration of the countryside is on foot.

6th SERIES 1 inch

6th Series Northern England and Wales maps were based on the Survey for the 4th edition; but Southern England and Wales, (South of Birmingham), were based on the 5th edition. From the 5th series on the maps were based on Lithographic masters (stone or zinc)- earlier these had been engraved. So, interestingly, Northern England and Wales 6th Series were still based on engraved masters, where as 6th series Southern England and Wales maps were based on masters which were already lithographic. In this 6th series M.O.T. road numbers were marked in red. Parish boundaries were re-established after a period of omission. Briefly a rather thick brown parish line was tried which compromised streams and other marks- this was quickly abandoned- I cite the Snowdon Map of 1918-1947 an an example of its use.

On Series 6 maps,the 1 kilometre National Grid was used for the first time. Work on the series began in the 1930s and was interrupted by war when all the effort of the OS went into Overseas mapping an War Office sheets. Then much preparatory work was lost in bombing raids and, having been halted in an unfinished state, many of the plates had not been photographed. Thus the maps which appeared as the “New Popular Edition Series 6″ in 1940- 1947 were much less “new” than had been intended as a result of the war damage to the Chessington or Southampton offices and the terrible oversight in not photographing working plates. When they first appeared the prices were: paper flat 2/6d; Paper folded 3/-; Linen backed and folded 5/-; Mounted in sections on linen 10/6d. Scottish maps use the same meridian and projection as England and Wales for the first time. Symbols appeared for National Trust, YHA, Wireless Masts, Pylon Lines, and Telephone Call Boxes. The only 6th Series Tourist map for which the reproduction material was not destroyed by enemy action was that of the Lake District. The other Tourist maps were recreated from scratch after the war. As most 6th Series are published from Southampton, perhaps it was there that the Ordnance Survey lost so much in Bombing raids.

7th SERIES – 1 inch

These maps generally appeared soon but not immediately after the war. The 1945-47 maps were Series 6. Series 7 was the first truly Post War survey- the survey revision work had mainly been carried out from 1946 to 1957- and the publications were initially from 1952 to 60- revised up until near the end of the decade.

On Series Severn Maps the war-time airfields were marked- usually just with the work “Airfield” an no details. 2 1/2” maps are needed for full runway and taxiway details. For this reason, Series 7 maps are better for war research than the contemporary Series 6 pieces. This series is particularly useful for historians of the RAF Fighter Command and Bomber Command , USAAF, RCAF, RNZAF and RAAF.

There are two formats. The earlier ones, from the end of the war have a folded format of 7 ¾ inches by 5 inches, they look noticeable dumpier and thicker. The later format was 8 ¼ inches by 5 inches. The sheet sizes were standard and did not alter- the difference lay in the folding, with the 1950 era maps having the map details or legend strip at the bottom folded-in before the main map was folded. The later format included the whole sheet in the main folds. Another age differentiator is the use of gloss covers. Generally these were later. Thus there are three instantly recognisable types for the 7th series Post War: (a.) Dumpy, matt cover with legend folded in; and  (b.) Larger folded size, matt cover, whole sheet folded together. c. Large folded size, gloss cover, whole sheet folded together. By the 7th Series, the railways were nationalised under British Railways and so the old company names disappeared. Closures had begun but Series 7 shows the full network, even if stationed are marked white – that is: closed. One cannot tell if a line so marked was fully closed or open to freight traffic only. It should be noted that the popular notion of “Beeching Cuts” is a simplification; it is quite apparent on Series 6 maps that many lines were already closing in the 1940s.

On Series 7 maps, Britain is seen before the motorway network. The Old fighter aerodromes are still shown, but not necessarily the operational ones. The following aesthetic changes from Series 6 can be seen: Woodland is apple green, not lime green. Urban areas are grey blocked, not black blocked. “A” roads are thinner, less vermilion, more crimson and they are numbered in red not black. “B” Roads are thinner, less ochre and more yellow and remain unnumbered. Tidal banks, bays and hydrographic features are marked in blue letters, not black. Contours are thinner and look lighter. Streams and rivers seem a little brighter blue- cobalt rather than tertiary. Orchards and plantations have a lighter and more widely spread symbol of trees in grey. Prices are no longer printed on the map legend. Towards the end of the 1960s the 1 inch series was printed in a plain red gloss cover with black lettering-this late series had a provisional look.

7th Series ½ Inch Green Covered OS maps:

An unusual. Perhaps provisional OS series. They used classic OS cartography with a very light toning in three colours and tan contour lines and colour also used for land-use so the series does not have the geological or “orographic” colouring of OS road maps and Bartholomew maps. This seems to be an experimental colouring form and it may not have endured long in published OS series. This series gives a very fine overall perspective of a region. Some detail was lost due to scale- notably orchards and plantations and minor stream names. But the hydrographic structure generally shows up better on this broader scale. There are aspects of the 1/2” series of the 1950s which suggests a much older template. Perhaps the Green ½ inch maps looked back to an earlier manner- perhaps that of the 1930s or even 1920s. Roads maintain a standard form irrespective of map scale- thus they dominate a 1/2 inch map more than a 1 inch map. This is a general characteristic of all small scale maps. Airports are generally absent- either due to war-time redaction which has not been reversed, or an older template which pre-dated they establishment. There are 51 in the series with Shetland being No 1. and Kent No 51. A standard sale price was 3/- for the paper map.

¼” Pre War, 3RD Edition Pocket Maps – For Motorcyclists ( & motorists):

These had boarded covers-which concertina the map between them. Front cover in black and tertiary blue on fawn with classic image of a motor cyclist studying his map by a road sign, in a peaked tweed cap, goggles, a double breasted tweed jacket and a Pre-1st War machine with a camphor lamp on a bracket square tank. Boards measure 7 ½” by 4 ¼” with G.R. Royal Arms (George V) at bottom front cover. Published from Southampton. Director General of the period cited: Colonel Commandant E M Jack CMG DSO. The map on linen cost 3/-, or Paper 2/-. The Grid is 2”; squares representing 8 miles or 64 square miles; one of the last non-metric grids published by the Ordnance Survey. All the Inter-War railways were named; jointly operated railway lines are marked as such. These are Geographical maps and show contours with graded colour , like a Bartholomew Map. The two publishers were in direct competition but Bartholomew used a ½ inch to the mile scale. Bartholomew covered more local regions- such as “Essex”; and Bartholomew were endorsed by the Cyclist Touring Club whose logo appeared on their map. Ordnance Survey opted for the smaller scale and pitched the map at motor-cyclists. They are similar to the large format blue covered 1/4” maps but have the county names printed in bold black lettering and have grid letters A to M down the sides, and numbers 1-15 across the bottom; a none standard system with no reference to the National Grid. Features marked include: Mineral Railways, Tramways, Battles, Lightships and Lighthouses and Seaplane Stations and aerodromes. These maps are often interestingly annotated by motorcyclists of the period. Numbering was as for the 1/4” 3rd Series large maps with the letter “A” added: 1A to 12A, but missing out 5A. The Index Map suggests that they may not have been issued for Scotland- and also shows that Nos. 1, 3, 10, 11 (Borders, North Yorkshire, Cornwall & Devon, and the South) were not produced in this compact series. Map details state that these were“Heliozincographed” which is “Photo Lithographed” . “Helio” means “using light” (i.e: photographically transferred) and “zincographed” means zinc-plate lithography. (“litho” means stone, the material of the first blocks.) Ordnance Survey and Bartholomew’s were rivals for the driver market and used similar formulae. It was a battle which Bartholomew probably won on cost and quantity. It is interesting how much extraneous sea was included on some (example: Isle of Man-North West England). This shows that any one O.S. Version is a by-product of a greater survey and project; the original raison d’etre having been military- not sight seeing by motor cycle.


These are large and blue-beige covered with the Royal Arms at the top front cover. There were two series, one for Scotland and one for England and Wales. Scotland numbered 1-9 from the Borders to Shetland, and England and Wales numbered 1-12 from the Borders to SE England. Number 1 was shared between the two series and covered the whole border from Solway to Berwick. Oddly, there was no Map 5 in the English Series and so England and Wales were covered by 11 maps. Map 10- Cornwall and Devon is different from the rest in that it did not overlap any other of the series at all. Scottish maps 8 and 9 were published together (Shetland and Orkney). The size folded was a large 12 ½” x 5”. The sheets were about 33” by 27” , with the legend border folded in separately, but they varied. Some, like Shetland, were much smaller. They were printed either portrait or landscape depending on which suited the geography best. They also has a sheet of city maps inside the back cover. This town map sheet was 22” x 12”, black and red on white and printed on recto and verso; it sometimes contained other information, for example: Sheet 4 shows Mersey Tunnel Charge. Typical dates were: Full Revision 1919- printed 1946 (4) so the print date equated with the 6th series 1” but the Master used was much earlier and would have been engraved or electrotyped- not lithographic. These maps have “orographic” colour gradation to show altitude and contour, they also have road numbers; it is apparent that they were going head to head with Bartholomew for the traveller and tourist and came up with a very similar manner of map making, but a very different large format- attractive but seemingly clumsy. In War time, these ¼ maps are sometimes found marked by flyers- particularly, on suspects, by Air Transport and Delivery pilots. These maps have Level Crossings predominantly marked in red because pilots followed railway lines and used level crossings as points of reference.

Original 1940s Prices; Paper flat 3/-; Paper folded 5/-; Mounted on linen and folded 8/-; An Outline only edition 3/-.


The 2 ½ inch small sheets are the best maps for local history, archaeological study and place-name study. They use black , blue and ochre, not full OS colour and will show individual buildings, trees, local names but not all field names. They are either uncovered, blue paper covered or blue glazed card covered. They measure about 18 ½ inches by 19 ½ inches and the black grids on them are 1 ½ inches or 4 cm across. They show and area of about 6 miles by 6 miles (36 square miles). The are number with 2 letters and 2 digits: such as TQ35. Each large area of the country, such as TQ is divided into 80 of these very local 2 ½ inch map blocks. The maps give farm names; they mark, but do not name, fields.

2 ½ Inch 2nd Series (Green)

This is a transitional series between the Blue single area format and the Pathfinder double area format. The Cover graphics are as the gloss 1st series 1:25000 maps showing a magnifying glass over a map. 1965 is a standard copyright date. The series anticipates Pathfinder in that the sheet is doubled longitudinally and the symbol legend is at the left. But the manner and printing quality is similar to the 1st Series without the “satin” feel or stark bleached paper of the later maps. The verso is plain, footpaths are bold and green; buildings are grey and individually drawn, ancient sites are well marked, field boundaries are black: This is more rarely seen series- very pleasant maps on good paper. The standard price was 8 shillings and 6d a sheet.

Pathfinder 2 ½ inch Maps

These were introduced circa 1980 and had a different format- They were larger, covering two of the old 2 ½” maps: Thus, for example, the Oxford map is marked SP40/50 and covered the old maps SP40 and SP50. Early Pathfinders had no other letter or number codes, but soon a new numbering system accompanied the Old letter and number grid: Example: “MONTGOMERY 909 : SO29/30.” One change is the return of Imperial scales, For a time from roughly 1960 onwards maps were described only as 1:25000, now “2 ½ inch to the Mile” makes a re appearance – perhaps by demand, because this means something; where as 1:25000 is rather abstract. The versi were now plain, which they had not been in the Provisional 1:25000 series, and the covers became Green and Rose Pink with Black and White lettering. Their printing differed from earlier 2 1/2” as well: Wooded areas became block green with tree symbols in black- previously they had been white with tree symbols in a grey. Symbols for trees differentiated between Coniferous, Broad leaf, Coppice and Orchard- Orchards alone retained the white background. The fonts changed too: Pathfinder lettering was Roman Capital Sans Serif and light. Older maps were Italic Capital and bold. Field boundaries where lined in a bold manner; previously they had been light grey. The orange contours lines were toned down and footpaths/ bridleways marked in a bolder green. Watercourses were a lighter blue and perhaps simplified with minor ponds being unmarked. The Fold format also changed from 24cm x 12cm to 24 cm x 12.5cm: seemingly minor but giving the folded map a markedly stockier look. The borders were changed: previously they had been white, now they were the same pale green as the woodland with an outer border in white. The paper turned from cream to white.

Underlying all these subtle changes was a shift in emphasis- old 2 ½ inch maps were documents of record with emphases on roads, altitude and water sources; perhaps land ownership and use was uppermost in the cartographer’s mind. The Pathfinder’s emphasis was on walking access- this had an advantage in the mapping of railways . Previously closed or closing railways used to undergo a gradual disappearance ending up with vague cutting symbols in the landscape. – but on these walking maps, they became boldly displayed in white with black lined edges; they had, with social change, become green-ways and important aspects of the countryside.

Local farm names were retained: but there appears to have been a change in the marking of tumuli and barrows which were now named but not marked with that circle of short dashes which had made then so prominent on the older series.

Overall the effect is of a higher key map with less geological emphasis and more right of way or leisure emphasis. The change from Capital Bold Italic to Light Roman Sans Serif, seemingly trivial, made a very big aesthetic difference.

2 ½ inch and its 1:25000 equivalent

Are these the same? Technically no. The maths works out as follows: 1 mile = 1760 yards, which is 5880 feet or 63360 inches. Divided by 2.5 = 1: 25,344. Which is the actual scale use on the map: 1:25,000, or 1:25,344? The 1:25,344 is the correct figure, the reference to miles is a convenient approximate for users. The 2 1/2 inch series was undertaken initially between 1945 and 1962- it was an entirely Post War exercise.

Geological Survey and Ordnance Survey

The relationship between the two Surveys was close. The BASE MAPS of the Geological Survey of Great Britain were always Ordnance maps, be they national or local. The definitive Great Britain Survey by the GSGB of 1948 , which was produced in 2 sheets (North and South), was 10 miles to the inch and used a grey OS base map. The Ordnance Survey retained primary copyright on these maps, not the GSGB. The Ordnance Survey published a large scale pair of sheets showing the Ancient Sites of Britain to accompany the Geological Survey- same format, also North and South, numbered 1 & 2, and using a grey-blue map base with orographic colour in ochre shades. These maps were very professionally produced with robust linen backs and were roughly 40 inches by 32 inches- as were the two sheet Geological Survey maps. The image on the covers of the two Great Britain Geological Survey maps of 1948 was very much in the manner of Ellis Martin but was signed “RTR” at bottom right: It showed a similar idealised English landscape with two geologists at work with hammer and map.

A characteristic of the accompanying 1951 Ancient Britain sheets was their conservatism- perhaps including only sites verified and surveyed by themselves- Piltdown was one unfortunate inclusion.

War Maps:

The Director of the Ordnance Survey in the 1st World War was Colonel Close. This war brought in the use of aerial mapping. Capt. Harold Winterbottom  was in charge of photo-observation from the air in this war.  33 million maps and plans were produced by the Ordnance Survey for the British military during the Great War. The Survey lost 67 of its personnel in the war. These maps were printed by the Geographical Section of the General Staff and published by the War Office- They have a different grid system to civilian maps – generally using purple lines and a reference system of vertical and horizontal numbers- East is read first, then North. The western edge of the square giving the East Co-ordinate and the south edge of the square gives the North Co-ordinate.

Interestingly these Military bearings conform neither to True North nor to Grid North. On many of these maps, MILITARY details are often printed under the map- on some, letters subdivide the chart. Some look cut down but it can be seen that they were issued without margins with coordinates printed across the middle of the map. The General scale for the local Military maps of the 2nd War is 1 mile to the inch. They are in full OS colour, but due to the many scratch printers used, the colouring is non-standard and the paper quality is War Standard. Smaller scale general maps are often found with air navigators’ hand written marks- They must have been used by Air Transport Corps.

The OS survey details are often given- original surveys usually being as early as 1865-78 and first publication often about 1876-82- then constantly revised until these War Time printings by the War Office Geographical Service.

One tends to find, when dated, that the GSGS OS maps with purple grid are 1930s surveys printed in War Revision of 1940 and the GSGS Blue Grid are generally 1940-42 prints of the 1940 War Revision.

There is considerable difference in colour on OS War maps. Generally the older and linen backed tend to use deeper lithographic colour and the paper and later maps tend towards muted lithographic colour. Tidal flats are shown in ochre on the former and often grey stippled on the latter. The blues of the fresh water and tidal water show the greatest difference between the series: quite intense and ultramarine on some (earlier)- more tertiary on others (later).

Military Maps have no covers, but are folded sheets, linen backed or paper and – often with a pencil reference on the verso. Often those that were used in the field had the edges folded back. A few were varnished- seemingly with cellulose- this was done to paper maps without linen backing. The standard size of the War Chart without margins is roughly 27 inches by 19 inches.

ADMIRALTY printings of the 1 inch OS -Seventh Series:

These are uncommon, use a cover indistinguishable from Civilian Ordnance Survey, but their linen backing is more robust and the printing details give the civilian publication date, normal reprint dates and then the words : “PRINTED BY THE HYDROGRAPHER OF THE NAVY” with a date. It might be assumed that these were coastal charts used for inshore water duties, maybe boat rescue, Air-Sea Rescue, fisheries and Coastguards. But one was found for Appleby Westmorland: it had no sea at all and no lakes of note- so their use is something of a mystery. Generally, cooperation between Admiralty Charts and Ordnance Survey was long-standing and sometimes cited on the map sheet: see notes of Jersey Maps. The main grid is National Grid and is set from Point 00,south west of Lands End. But there are also a grid in degrees north and east-west of Greenwich marked with a light cross- the grid has 5′ squares (five minutes: a minute being a 60th of a degree). This “true longitude-latitude grid” is also marked on land but is difficult to see- it becomes a major feature of the hydrography. On land this cross might be confused with a symbol for a site of antiquity or a church without a spire: but it is longer and lighter than those.


In some series this is treated as a different survey with different lettering and numbering systems. On War Maps this is the case (1” small sheet, blue, purple grid) and when a map crosses the Border- for example the sheet “ Solway-Gretna-Longtown”- it has two numbers, one for the Scottish Survey and one for the English and Welsh Survey. However, how much the two Surveys were ever independent is a debatable point and will be noticed that the Ordnance Survey of Scotland Maps are published by the Director General from either Chessington Surrey or Southampton, Hampshire. The covers on Vintage OS maps were different; the English and Welsh Surveys showed the Royal Arms not the English Arms, the Scottish Survey showed the Lion Rampant, not the Quartered Arms of the Monarch in Scotland, which would have been the Lion Rampant 1st and 3rd, Three Lions 2nd and Harp 4th with the supporters of the Scottish Arms; the implication might be that the Ordnance Survey of England and Wales was under Royal Patronage, where as that of Scotland was not. From Series 7 onwards Scottish OS maps used the same hinged cover system as English OS maps- prior to that Series Scottish maps had a concertina cover system. Scottish series 7 maps still retain the Lion Rampant arms.


The 1914 Jersey Survey produced a non-standard 2 inch to the mile map which used contours and a tan shading to display the geology of the island. It referred back to 1900-01. The covers were pictorial showing a scene from the Island. Prehistoric sites and old forts were shown and the Jersey Railway was an important feature of the eastern side of the island. The map was corrected in later years with reference to the Admiralty charts and this, plus the manner of printing and presentations- suggests that it was always envisaged as an aid to sailors and as a map for visitors. The rocks of the Jersey coast and the marine lights were recorded in a manner reminiscent of the detail of a marine chart. The map was folded and had hinged covers, and a smaller format when closed.


A rare map, the example described is 1933- Scale 2 ½ inches to the mile, geologically coloured-with ochre and light shading to represent the hills, orange contour lines. Map 25 ½ “ x 22 inches- all coloured roads are ochre- either solid or dashed- minor tracks uncoloured. This is called a Special District relief Map- Woodland is green. The Admiralty is cited for the submarine contours. The grid is 1-4 of longitude from west to east and A to C of latitude from north to south. Grid squares are 5 ¾ inches or perhaps 3 miles in each direction. Drawn on a Transverse Mercator projection- the boundaries marked at sea are parish borders. Published from Southampton in hinged fawn card covers with a red block printed Royal Arms called “Fifth Relief Edition Isles of Scilly” under the auspices of the Ministry of Agriculture and Fisheries.


The START POINT is a little to the south west of Lands End and then all the points in England and Wales (later Scotland) are pin pointed in reference to east and north of this point. This point “0” then forms the default position for a grid of 10 km squares, subdivided into a 1km grid, drawn parallel to a North South line through Point 0. The eastings are then given followed by the northings to pin point any place. A 4 letter reference gives you a point within 100metres. a 6 letter reference give a point within a metre. On a very local map you can scrap the 100s of kilometre number- and give just 3 numbers 356- 532 for example : square 35.6 east and square 53.2 north. Of course you cannot portray a globe accurately in this way and so the distortions by the time you are in say Berwick, Cromer or Shetland are quite considerable. This may have been the logic behind Scotland having its own perspective point and grid which seems to have ceased in series 6. It seems logical that eastings would distort more than northings; a northern line from Start Point 0 is correct irrespective of its length- though “true north” moves on a planet which wobbles in its yearly orbit. Longitude line east of Point 0 should converge. The National Grid does not show Mercator grid elongation. The National Grid perhaps shows that cartography is an art of convenience,and subjectivity as much as a science. When this system was introduced, it was explained in full on the inside of the front cover- Series 6 was contemporary to its introduction, and all Series 6 maps carry this explanation.

Tourist Maps:

These are perhaps the most attractive of the OS series combining “orographic” colour and contour- the early ones were intaglio and the series was substantially lost in the 2nd World War due to Bombing Damage. The Lake District was the only Master which survived the destruction. The Post War  Tourists’ lithographic maps were 1” and the orographic colour is quite different from that of Bartholomew- more high key, brighter. The mapping is “hybrid”, having relief colour, contour and shading- they tended to have the large format of 41” by 33 inches and the covers were particularly attractive in the early 19th century with period graphics evoking the age. The covers of the 1960s were a little bland and perhaps did not do justice to the excellent maps within which aspired to the condition of art as well as documents of information.


The multi plate coloured intaglio printing of the Early 20th century Tourist series represents perhaps the most interesting an attractive of all Ordnance Survey maps.

Very Rare maps: there are several but two are the semi mythical Engraved maps with railways before electrotyping and the 1927 Eclipse Map with pictorial cover- A map for a one day event.

Trig-Point: Spot Heights. The Ordnance Survey built these between 1935 and 1962. In  flat land where heigh points were not to be had for survey work the Survey built temporary high points with “Bilby Towers”.



The standard way is: fold the map horizontally, then concertina the map laterally, Fold in half. (If the lower information border is separately folded, that is done first.) Scottish OS maps used a floating cover system, as did Bartholomew of Edinburgh. Often the front and back boards of a concertina-folded map were not on the same horizontal line of folds. The OS Motorcycle Maps have floating covers as well. The advantage of the Scottish system was that one did not get hinge wear on the cover. The disadvantage of the Scottish system was that there is no spine with map details readable from a library shelf. Scottish OS maps used hinged covers from Series 7 onwards.

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