Chapter I: The Institution of National Surveys

The earliest surveys were not laid down as maps but consisted of catalogues of property which are called "terriers;" of these the Domesday Book is the earliest extant. Had the art of surveying been properly understood at the time of the Norman conquest there would probably have been a Saxon cadastre along with the Domesday Book, which was ordered by William the Conquerer in the year 1085.

"After this had the king a very large meeting, and a very deep consultation with his council about this land, how it was occupied, and by what sort of men. Then sent he his men all over England, into each shire, commissioning them to find out 'how many hundreds of hides were in the shire; what land the king himself had, and what stock upon the land, or what dues he ought to have by the year from the shire.' Also he commissioned them to record in writing, 'How much land his archbishops had, and his diocesan bishops, and his abbots, and his earls; and though I may be prolix and tedious, what and how much each man had, who was the occupier of land in England, either in money or in stock, and how much money it was worth.' So very narrowly indeed did he commission them to trace it out, that there was not a single hide nor a yard of land (the fourth part of an acre), nay, moreover, (it is shameful to tell, though he thought it no shame to do it) not even an ox, a cow, or a swine was there left, that was not set down in his writ, and all the recorded particulars were afterwards brought to him."--_Saxon Chronicle, by Ingram_.

The publication of the Domesday Book was ordered first by George III. in 1767, and completed in 1783. After the discovery of the art of photozincography it was reproduced "in facsimile" in 1864-5, under the direction of Lieut.-Gen'l. Sir Henry James, then director of the Ordnance Survey.

Little change (in the art of mensuration or surveying) seems to have been made until the early part of the 17th century when simple boundary line maps accompanied the terriers of the surveys made in Ireland in 1634, by order of Lord Stafford, then viceroy. Great improvements were introduced about that time in Sweden by Gustavus Adolphus, which must have become known to Cromwell, for in 1654, the "Down Survey," as it was called, comprised maps of the townlands, and baronies over two-thirds of the surface of Ireland, that is, comprehending about 20,000,000 of English acres.

It may not be uninteresting or irrelevant to bestow a few remarks upon the development and methods of surveying in the seventeenth century, many of which have descended with little modification to the present day.

When man first conceived the idea of owning real property the art of geometry or surveying became a necessity. Interest in other worlds than our own, and the measurement of time, led to the development of the science of astronomy, and of graduated instruments for measuring angles. Many of the most refined modern instruments are but slight modifications of original Arabian models, and the practice of linear surveying, or the subdivision of land into triangles, and geometrical figures, whose area could be computed, has been carried on without modification for centuries.

The greatest development took place after the introduction of artillery in the methods and instruments used for trigonometrical surveying or range-finding. Every principle which is to-day known and applied in the construction and use of modern trigonometrical surveying instruments can be traced in a modified form to the construction and application of the instruments of the sixteenth and seventeenth centuries.

In the practice of artillery, the first important question is the distance or range of the enemy. As in war it was clearly impossible to obtain the same by direct linear measurement, instruments were devised for measuring the range trigonometrically, all based on the calculation of a single triangle, the base and two angles of which could be measured. These instruments were simply modified to the extent of furnishing in the instrument itself a constant base or angle so that only one or at most two measurements were necessary.

The one instrument that has received the greatest development in the modern type is the quadrant, a simple graduated arc from whose center was suspended a plumb-line, or which carried a movable arm with raised sights for measuring horizontal or inclined angles. This arm has retained the name alhidada derived from the Arabic.

Such was the trigonometrical instrument used by the earliest navigators and astronomers for determining latitudes, and by surveyors and artillerists for finding ranges.

In the latter part of the 16th century Thomas Digges, surveyor and author, conceived the idea of combining two such graduated arcs in one instrument, the one placed horizontally and the other in a vertical plane, the whole supported on a rigid stand or tripod, and he called the same his _Theodolitus_, which is said by DeMorgan to have been the origin of the name of the modern instrument.

In the earliest books in the practice of artillery and of surveying, the crescent of the dreaded Moor appears in the woodcuts illustrating range finding or trigonometrical surveying generally floating over the tower of some captured castle or town, which it is desired to bombard. This clearly demonstrated that the chief use of trigonometrical instruments was for military purposes.

Among the instruments of surveying of this period which became practically obsolete in England in the present century, but which is most widely used elsewhere, is the plane-table, unquestionably one of the earliest instruments invented for measuring or recording angles.

At the period 1570, when the Germans claim that it was invented by Pretorius, a professor of the University of Nuremburg, it was unquestionably in use in England, and it is mentioned by Thomas Digges, in his _Pantometria_, published in 1590, as a platting instrument for such as are ignorant of arithmetical calculations. On the relative merits of the theodolite and plane table authorities still differ.

Throughout Europe great activity in the development of the practical applications of geometry soon followed the exchange of ideas brought about by the introduction of printing.

Side by side with the important geographical discoveries of the age came the minor improvements in scientific instruments which rendered national surveys and geodetic operations possible at a later period.

With trifling modifications the instruments devised by Durer, Newton, and Gallileo are in common use to-day.

Gradual improvements can be traced in the application of surveying to military and civil purposes, to mapping the campaigns of Louis XIV. and Marlborough, and laying down the forfeited estates in Ireland by William III., until in 1729 the first national survey on a large scale, for public and private purposes, was commenced in Savoy and Piedmont by Victor Amadie II., whereon nine years were occupied.

The method of large surveys obtained the name of Cadastre (Terrier map). It was suggested for France in 1763, but was only commenced in that country in 1793. The exact derivation and meaning of the French term "cadastre" are not free from dispute. Some authorities refer it to the verb "cadrer" to square or correspond with, all objects on a large scale, plan, or cadastre being shown in their true position and proportions, whereas in a mere topographical map similar accuracy is impossible, and certain features must need be exaggerated for the sake of distinctness.

The _Dictionaire des Dictionaires_ on the other hand derives _cadastre_ (formerly capdastre) from the mediæval-Latin word capitastrum (from caput "head," because formerly people were taxed, and afterwards property) and defines it as "a public register, containing the quantity and value of landed property, names of owners, etc., and which serves for the assessment of the tax on property in proportion to its revenue."

In the _Recueil des Lois et Instructions sur les contributions directes_, the _cadastre_ is defined as "a plan from which the area of land may be computed, and from which its revenue may be valued."

This, there is no doubt, is the sense in which the word is used on the Continent, while in England it is taken as denoting generally a survey on a large scale.

It was not until long after the organization of the Ordnance Survey that it became a cadastral survey. Its organization at first was distinctly for military purposes, and the extension of its operations to cover all national needs only attained after years of discussion, and struggle for existence.

The credit of originating and carrying into execution the first tangible project for a systematic topographical survey of part of the kingdom is divided between two engineer officers, both at the time holding distinguished positions on the staff of the British army. The idea would seem to have followed close upon the sanguinary termination at Culloden of the "forty-five" rebellion, by which the fate of the house of Stuart was decided, in the reign of George the Second.

It was doubtless the outcome of that unhappy rising for it contemplated a general map of the Scottish highlands, precisely those parts of the country in which the heart and soul of the insurrectionary movement had all along centered. The difficulties of moving troops through these wild mountain districts, and without any clear knowledge of the passes connecting the glens and fastnesses, or of the correct distances intervening, would have been enormously lessened by the possession of good maps.

The survey of this wild and inaccessible region was undertaken in 1747 by Lieutenant-General Watson, an engineer, ably assisted by William Roy, who afterwards played a distinguished part in the earlier geodetic work of the Ordnance Survey.

The map, at first intended to be confined to the Highlands only, was at last extended to the Lowlands and thus made general in what related to the mainland of Scotland, the islands (except some lesser ones near the coast), not having been surveyed.

It is spoken of by Lieutenant-Colonel White, in his excellent book on the Ordnance Survey, as a "piece of work which appears to have been excellently carried out as far as it went, qualified by the remark of Roy that owing to the comparative inferiority of the instruments used and the inadequacy of the annual grants provided for the survey it is rather to be considered as a magnificent military sketch than a very accurate map of the country."

The survey of Scotland was interrupted by the breaking out in 1755 of another of England's intermittent wars with France, that which gained her Canada, and the work was never completed.

"On the conclusion of the peace of 1763," writes General Roy, "it came for the first time under the consideration of government to make a general survey of the whole island at the public cost." But, for reasons not assigned, the twelve years' interval of peace before the outbreak in 1775 of the American War of Independence was allowed to pass away without anything being done. There the matter remained in abeyance until, after renewed hostilities with France and Spain, peace was negotiated in 1783.

The trigonometrical survey of Great Britain may be said to have been begun one hundred and six years ago.

Astronomers of that day were desirous that the difference of longitude between the Greenwich and Paris observatories should be ascertained by trigonometrical measurement; and under the auspices of the king and of the Royal Society, General Roy, R. E., in April, 1784, began the task by the measurement of a base line on Hounslow Heath which was to serve as the starting point of a series of triangles to be extended to Dover and across the channel.

This work was carried out, a connection with the French triangulation being established in 1786.

Soon after this the government decided on having a general survey made of the entire kingdom, on the scale of one inch to one mile for military purposes, and General Roy's triangulation in the southeastern counties became the basis of the Great Triangulation, which was gradually extended over the whole of the British Isles and finished in 1853.

The one-inch survey was carried northward through England and Wales under the successive superintendence of artillery and engineer officers, and by 1824 had reached the southern borders of Yorkshire and Lincolnshire.

At this time it became necessary that a survey of Ireland should be made on a large scale as a basis for general land valuation. On the recommendation of Colonel Colby, then director, the scale of six inches to one mile was agreed upon; the work in England was suspended and the force transferred to Ireland.

It appears from a report of Colonel Colby, in 1840, that the purposes for which the English and Irish surveys were designed were gradually developed and not all originally known.

The principal triangulation, on which the survey of South Britain had been based, was partly designed for astronomical purposes, and partly for a map on small scale.

The detail plans were commenced by officers of the Royal Engineers, partly for the purpose of practicing them in military drawing, and partly for the purpose of making plans for the use of the Ordnance.

The publication of some parts of this map on the scale of one inch to one mile created a desire among the public to possess better maps than had formerly existed.

This led to the employment of civilian surveyors to advance the progress of the map, and it was found necessary at great additional expense, to revise and correct these contract plans.

The work did not possess the accuracy demanded by the admiralty in forming the basis of their coast surveys for the Geological Survey or the civil engineers. As a military map its publication during war was suspended, and its continuance became a matter of doubt in time of peace.

At one time the gentlemen of Lincolnshire and Rutlandshire proposed to the government to proceed with the map of their district out of its regular turn, upon condition of their becoming subscribers for a certain number of copies. These gentlemen partly wished for the map for their use in hunting, and partly for the improvement of the country in marking out the drainage of the fens.

Prejudices existed, which could be traced back to the Norman conquest and Domesday Survey--against the right of a surveyor to enter a private estate, and in the early contract plans for the English maps the surveyors neglected the survey of the lesser streams, to obviate the inconvenience of trespassing and to save themselves trouble.

These were some of the causes of delay, expense and insufficiency which had operated against the earlier surveys.

The survey of Ireland began in 1825 under far more favorable circumstances than the Ordnance map of England and Wales. The triangulation commenced from a more accurate baseline than any preceding triangulation, and was designed to serve as a basis for any future survey in any scale, however large.

The House of Commons passed an act defining its principal object, prescribing a legal mode for ascertaining the boundaries which were to be surveyed, granting the surveyors power to enter lands for the purposes of the survey, and preventing the removal of the objects used.

The earlier methods of military surveying were abandoned, and new instruments and a system were devised for its execution.

It is important to note that the organization of the Irish survey marked an important epoch in the history of the Ordnance Survey, viz: its change from a topographic to a cadastral survey.

In Ireland, subordinate to the parishes, there is an internal division of smaller denomination called townlands, which are very frequently, but not uniformly, conterminous with property.

The townland was the lowest unit of taxation for country purposes, of an average size of 200 or 300 acres, and originally the map was to be simply a topographic map, containing the boundaries of the townlands, the roads, the streams and the houses, with a view to the valuation of Ireland for the county assessment. The six inch was considered to be the smallest scale that could be available for that purpose.

There was no intention in the original Irish survey to insert the fields, but when the valuation began, it was found by the valuators that additional minuteness was necessary to enable them to subdivide the townlands into the qualities of lands of which they consisted, and more especially that the boundary between the cultivated and uncultivated portions ought to be inserted on the maps with great accuracy.

This rendered necessary a very extensive revision which was undertaken in 1830, and it became a survey by fields instead of townlands.

This was clearly a wide and most important departure from the original intention of the six inch survey in Ireland, and it is not to be doubted that General Colby, who would not trust to paper measurements for the areas of entire townlands, would have adopted at the very outset, for his manuscript plans of these minute subdivisions, a scale much larger than that of six inches to one mile.

The engraving of the six inch survey appears to have resulted from a demand for six copies of one sheet for valuation purposes when it was found that it would be as cheap to engrave it as to make that number of copies.

So valuable did the six inch map of Ireland prove for many purposes over and above that for which it had been originally designed, that, in 1840, when the Irish survey was completed, and that of England resumed, the Government gave their consent to the adoption of the same scale for the unsurveyed parts of Great Britain.

By 1851, Yorkshire, Lancashire, the Isle of Lewis, and several counties in the south of Scotland were finished on the six inch scale.

Then began that long controversy which has been well termed the "battle of the scales" and which for eleven or twelve years retarded the progress of the survey and led to a large waste of public money.

During the time that the Ordnance Surveyors were engaged in making their six inch map of Lancashire and Yorkshire they were called upon and employed to make, at the expense of the land owners, twenty-three plans of parishes and townships on the scale of twenty-six and 2/3 inches to one mile for tithe commutation.

It was even found that the plan of London, made for the Metropolitan Commissioners of Sewers, on the scale of sixty inches or five feet to one mile was inapplicable to house drainage within the area.

Between 1851 and 1852 no fewer than three select committees and one royal commission deliberated on the scale for the survey, and fourteen blue books were presented to Parliament.

The main point of the controversy was whether the six inch or some larger scale was best fitted for the national map. A host of persons eminent in science were consulted on the subject, and a great diversity of opinion was found to exist, the weight of evidence, however, inclining by a majority of four to one, to a scale of from 20 to 26-2/3 inches to a mile.

In 1853 a statistical conference held at Brussels and attended by twenty-six delegates from the chief States of Europe considered the question of national maps or cadastres, and pronounced unanimously in favor of a scale of 1/2500th of nature equivalent to about 25-1/3 inches to a mile, recommending at the same time that the cadastre on this scale should be accompanied by a more general map on the scale of 1/10,000 equivalent to about six 1/3 inches to a mile, and thus very nearly corresponding to the six inch scale of the Ordnance Survey.

The scale finally adopted of 1/2500, on which the whole of England has at last been surveyed, is one which corresponds with that adopted for the national maps and plans of the chief countries for Europe. Lastly it possessed the incidental advantage that a square acre is to all practical intents represented on the plans by a square inch.

Among the many public purposes which the national map was expected to subserve are the following: the valuation of property for the equitable adjustment of taxation and assessment; the sale and transfer of land and the registration of title; railway and other civil engineering work, such as the construction of roads and canals, large sanitary and drainage schemes, military engineering works, hydrographical, geological and mineral surveys; the reclamation and improvement of waste lands, and of land from the sea; transactions affecting land as between landlord and tenant; statistical surveys, the setting out and adjustment of parochial and other public boundaries and so forth.

It has been amply proved on the best evidence that a map, with levels, on a scale of something like twenty-five inches to one mile is the smallest which can properly fulfill all these requirements.

In the organization and equipment of the Ordnance Survey, as it exists to-day, no pains are spared to secure the utmost precision and economy in its methods of field work and publication.

After more than a century of development and the completion of the cadastral map, let it not be supposed that its mission is at an end, for it is proposed to make a complete revision of all the cadastral work at least once every twenty years.

This is rendered necessary by the constant changes in property boundaries, and the growth of population--which may be gathered from the fact that the city of London increases in population at the rate of about 50,000 a year, and that eighty or more miles of new streets are added in the same time.