1. 1747-1840
The origin of the Ordnance Survey is to be found in operations between 1747 and 1755 for the production of a military map of the Highlands of Scotland. Schemes for an extension of the Survey to the rest of Britain, however, received no support until 1784, when Major General William Roy triangulated south-east England from a base line on Hounslow Heath, west of London. In 1791 a new trigonometrical survey was appointed under the direction of the Master General of the Ordnance. The trigonometrical survey had two main tasks: the production of a military map based on an accurate triangulation, and the publication of a map for general use.
The first official map by the new Ordnance Survey, that of Kent at a scale of one inch to the mile, was published by William Faden in 1801. The second one-inch map, that of Essex, was the first map directly published by the Ordnance Survey. Between 1811 and 1817 and between 1824 and 1840, work ceased on the production of the one-inch maps, because of financial stringency and work on a survey and valuation of Ireland.
The Ordnance Survey became a separate department in 1841. Much information about its activities before that date can be found in the records of the Board of Ordnance, particularly in WO 44, WO 47 and WO 55. There is also material among Treasury records in T 1. Some records earlier than 1841 are to be found in OS 3, particularly the military and scientific papers of Major General William Roy, 1756-1791 (OS 3/1-5).
2. 1841 to date
The Ordnance Survey Department was constituted by the Ordnance Survey Act 1841. During the nineteenth century the practical value of accurate maps came to be more fully appreciated. Maps were vital for national defence, for the management and transfer of land, and for civil engineering (especially roads, canals and railways). By the mid-nineteenth century, the Ordnance Survey was assuming its modern role of providing, as a national service, the surveys and maps of Britain required for government, military and general public use alike.
The First World War was a watershed in the history of the Ordnance Survey. Revision of maps was slowed down and the establishment of the Survey was reduced to 1,000 people. By the early 1930s, although some activities had been left unscathed, it was clear that successive economies had left the Ordnance Survey ill-equipped to meet the tasks expected of it. A departmental committee under Sir JCC Davidson was set up in 1935: it recommended a programme of expansion and revision, which was delayed in application until after the Second World War. This application of the Davidson Report remained the basis of Ordnance Survey practice until recent changes in technology. Papers of the Davidson Committee are in OS 1/113-121.
In 1985 the Ordnance Survey absorbed the Directorate of Overseas Surveys, records of which are in OD 5 and OD 6.
Administrative files of the Ordnance Survey are in OS 1. Very few files survive from the period before the Second World War, as a great many papers were destroyed during air raids on the Ordnance Survey building in Southampton in 1940 and 1941. Some administrative and related papers are in OS 3. A series of policy papers is in OS 11. Annual reports of the Survey, which describe the work of the Survey year by year and list maps published, are in OS 9. Office notices and circulars are in OS 8.
For a general history see W A Seymour (ed), A history of the Ordnance Survey, (1980).
3. The public boundary archive
The Ordnance Survey Act 1841 laid on the Ordnance Survey the duty of ascertaining and recording all public boundaries in Great Britain and effectively required the Ordnance Survey to create a permanent archive of the public boundaries of Great Britain. The position of a boundary on the ground was to be determined in relation to surveyed natural or man-made features and incorporated in new editions of published Ordnance Survey maps.
The initial information obtained in the execution of this duty was recorded in a boundary remark book (to be found in OS 26), and information about and authorisation for place names were recorded in the parish name books (OS 23). Similar information about names of places within parishes is contained in the original name books (OS 34). In due course, the parish name books were superseded by boundary record maps (in OS 31 and OS 33). In cases of disputed alignment, all the evidence was examined, a boundary report (OS 32) was drawn up and a final decision was made by the Director General. The boundary was then redrawn if necessary on a boundary sketch map (OS 27), and any amendments were noted. The boundary sketch map was then publicly exhibited, and members of the public were invited to record any comments in the journal of inspection (OS 29) which was provided for the purpose. Official action in response to such comments was also recorded in the journal. The agreed boundary alignment and administrative names were subsequently shown on published six-inch maps.
Maps lodged with the Ordnance Survey under the provisions of an Act or Order are called deposited maps. Such maps relating to England and Wales are in OS 38, and those relating to Scotland are in OS 39.
There are several series of correspondence relating to boundary changes. Correspondence on areas within poor law unions between 1840 and 1940 is in OS 24; OS 30 contains similar correspondence relating to Scotland; OS 37 relates to the period between 1940 and 1971. A few miscellaneous files are in OS 12.
Many series of administration area diagrams showing local government and parliamentary boundaries are in ZOS 2. They cover the period between 1890 and 1960. Several earlier series of diagrams are in OS 3.
An index to the tithe survey for England and Wales on old series one-inch maps, a project which was completed only for the area south of a line between Preston and Hull is in ZOS 6. These maps show the boundaries of the tithe districts created for the administration of the Tithe Commutation Act 1836.
4. Staff records
Very few records of genealogical value survive amongst the records of the Ordnance Survey. Many early records were destroyed in a fire, at the Tower of London in 1841 or during air-raids on Southampton in 1940. The Ordnance Survey at Southampton holds no records which could help the genealogist.
Between 1790 and 1805, cartographic work was carried out in the drawing room of the Ordnance Survey by civilians working under Royal Engineer officers. In 1805 the civilians were formed into the Royal Corps of Military Surveyors and Draughtsmen. The Corps was disbanded in 1817. A card index to names of people who served either in the drawing room at the Tower of London or in the Corps itself is held at The National Archives and may be consulted by arrangement. The index is based on information in WO 54/208 and other documents, and contains dates of appointment and promotion.
After the Napoleonic wars, the Survey's work was extended to undertake a survey of Ireland. To aid this operation a regular and disciplined labour force was provided by the formation in 1824 and 1825 of three survey companies, the 13th, 14th and 16th companies of the Royal Sappers and Miners. Another company, the 19th, was formed in 1848, and all four were transferred to the Royal Engineers, from which their officers came, in 1856. The 16th company was disbanded in 1906, and the remainder reconstituted as the Survey Battalion, RE, in 1929. With the altered conditions after the end of the Second World War the Battalion itself was disbanded in 1946. These survey companies did not function as ordinary Royal Engineer Companies, the personnel being distributed throughout the Survey.
Until after the Second World War, men serving with the Ordnance Survey might be either Royal Engineers or civil assistants. It should be remembered that only a proportion of the staff of the Ordnance Survey was in the Royal Engineers; information about the military careers of these men may possibly be found among the records of the War Office. Officers and men serving with these companies were ordinary military personnel, whose records can be traced in exactly the same way as those of other servicemen.
Several Ordnance Survey records may also be of assistance. OS 1/1/1 contains an unindexed list of Royal Engineer Officers who served in the Survey between 1791 and 1927. A register of deceased soldiers serving in 13 Survey Company between 1829 and 1892 is in OS 3/300. This register gives information about the cause of death and the disposal of the man's effects. OS 1/1/4 has a list of all Royal Engineers serving with the survey on 1 July 1890.
A register of marriages of men serving in 16 Survey Company between 1901 and 1929, together with the birth dates of children, is in OS 3/341. OS 3/275-277 contain seniority lists of the Survey Battalion between 1935 and 1942.
From the earliest days of the Ordnance Survey, the majority of the personnel working at the Survey were civilian, yet it is considerably more difficult to find anything about these people. As the name suggests, civil assistants were surveyors and draughtsmen employed to help the military. Many civil assistants were former Royal Engineers who had previously been with military survey companies. The best source of information about civil assistants is OS 3/285, which is a register giving dates of entry into the Survey and retirement. It is not indexed. A complete list of civilian staff in post in the Survey on 31 March 1863 is to be found in the parliamentary papers 1862 (xxxiii) 505. OS 1/1/4 contains a list of all civil assistants as well as Royal Engineers in post on 1 July 1890. A very few personal files on senior staff are in OS 10.
5. Technical records
Relatively few technical records of the Survey have been transferred to The National Archives. Policy files on all aspects of scientific work are in OS 1. Other scientific material is in OS 3. Files of the directorate of Field Surveys are in OS 13. Experiment files are in OS 14. Certain records of the original triangulation are in OS 2. Liverpool levelling books and abstracts are in OS 17. The original triangulation did not provide satisfactory coverage, even after the figures were re-worked and reorganised as the principal triangulation in 1855. A further retriangulation of Britain was begun in 1935 and completed in 1962. Administrative files relating to this work are in OS 1. A few books relating to magnetic surveys of Great Britain are in OS 6; some related maps are in OS 5. Fieldwork documents of the Survey created during the planning and building of the Cambridge radio telescope are in OS 18. Specifications and proofs of small and medium scale maps are in OS 36.
6. Miscellaneous records
Parish Acreage Lists, which give the total areas of land and water in each parish, are in OS 4. Papers and returns of the 1865 Survey of Commons and Open Spaces within a 25 mile radius of London are in OS 25. A series of maps showing the military grid overprinted on one-inch and quarter-inch maps during the Second World War is in ZOS 3. London Underground Railway plans, dating from 1948 and at a scale of 1:1,056, are in OS 7. A few maps created for the War Office are in OS 43. A set of ten mile to the inch maps is in ZOS 4. History maps, showing historic sites relating to particular periods, are in ZOS 5.
Other series of maps, together with individual examples created by the Survey since 1790, are in OS 3 and OS 5. Samples of printed material produced by the Ordnance Survey are in OS 3.
7. Ordnance Survey maps in The National Archives
The National Archives is not a place of deposit for successive editions of published Ordnance Survey maps. Readers requiring specific sheets of known editions and scales would be better advised to enquire of the British Library map library or another legal deposit library. However, The National Archives have very large holdings of published Ordnance Survey maps. A set each of the old series and the new series one-inch maps is in the reading rooms at The National Archives. Provisional edition six-inch national grid maps are in ZOS 1.
Extensive accumulations of Ordnance Survey maps are scattered among the records of other departments. Particularly rich sources include the records of the Forestry Commission (F 17, F 23, F 30); the National Coal Board (COAL 40); the Tithe Redemption Office (IR 90, IR 93, IR 105); the Valuation Office Survey (124 series from IR 121/1 to IR 135/9); the War Office (WO 78); and the British Transport Historical Records (RAIL). There is no single cumulative index to the sheets represented in these and other series.
