884 



ORDNANCE SURVEY 



on a scale of 6 inches to a mile ; kingdom, a 

 general map 1 inch to a mile. 



The sheets of the 1-inch map join together, to 

 a* to form a complete map of the whole kingdom. 

 Thin is true also of the sheets on the 6-inch and 

 ,fn scales of each county, but the sheet* of 

 different counties, except when drawn to the same 

 meridian, are not connected. The n"sj scale 

 also applies only to cultivated, populous, and 

 mineral districts ; the Highland* of Scotland, and 

 other extensive moorland and uncultivated tracU, 

 being only surveyed on the 6-inch scale. 



The scale, originally 1 inch to a mile, was 

 increased to 6 inches to a mile when the survey 

 reached Yorkshire and Lancashire ; these counties 

 being done on that scale as well as on the 1-inch 

 scale. The remaining counties of England were 

 done on the scale of 25 inches to a mile for culti- 

 vated districts, ami on U inches to the mile for the 

 uncultivated ami moorland districts. When Eng- 

 land was completed a re-survey was l>cgun on the 

 J inch scale of those counties which had only been 

 surveyed on the I -inch scale. The sheets on the 

 scale of 25 inches to a mile (called parish maps) 

 are reduced by photography, and issued on the 

 scale of 6 inches to a mile* (county maps). The 

 1-inch maps are again reduced by photography 

 from the 6-inch, and are being published in outline 

 only and also with hills. The survey of the whole 

 of Scotland was completed in 1877, and the maps 

 for the whole area, on either the 25-inch or 6-inch 

 scales, have been published. On the 1-inch scale 

 two editions are published, one in outline only and 

 another with hills. In Ireland, as stated, the 

 6-inch maps have been long piililixlied, and are 

 now in process of revision, and a survey on the 

 25-inch scale has been commenced. A 1-inch map 

 of the whole in outline, ami, with the exception 

 of a few sheets, an edition with hills have been 

 published. In all the three kingdoms plans of 

 many of the towns on the 10 and 5 feet scale are 

 also published. 



The sketch now given of the history of this 

 great national undertaking will show that it has 

 been conducted at different times on different 

 scales and plans, and that the system now pursued 

 was only adopted after much discussion both in 

 parliament and out of doors. The map was origin- 

 ally licgiin as a military map, and the scale of 

 1 inch to the mile chosen, without considering 

 whether some other scale would not offer greater 

 advantages. Many now think that a scale a little 

 larger, and an aliquot part of nature, such as 

 Yiit or about 1J inch to the mile, would have 

 been preferable for the small map ; in which case 

 a scale of i-jloj of nature, or about <i.\ inches, 

 plight have been chosen for the intermediate, 

 instead of the 6-inch scale selected at first for 

 mere local purposes in Ireland. lie this as it may, 

 the arguments in favour of the 1-inch map arc 

 that it is the most convenient lx>th as a general 

 and travelling map. For general views of the 

 structure of a country, the distribution and rela- 

 tion* of it* mountains, plains, valleys, and rivers, 

 the 1-inch is admitted to be superior to the 6-inch, 

 and thus better adapted in the lii-t instance for 

 laying out roads, railways, or other extensive public 

 work*, or for the publication of n general geological 

 survey. Such a map, on the otlu>r liaml, is on ton 

 small a scale to admit of correct measurements of 

 mall distances ; it is in some respects a generalised 

 picture and not a correct plan. The 6-inch maps 

 v ere at first selected in Ireland as the smallest size 

 on which correct measurements of distances and 

 areas could be made. On them every house and 

 field, and almost every tree or bush, might be laid 

 down. Hence they are superior for working out 

 details, ai in minute surveys of railway* or roads, 



or the complex geological structure of rich mineral 

 districts. On such sheets, too, a proprietor or 

 farmer may find every field laid down, and the 

 relative heights indicated by contour lines, and 

 may therefore use them for drainage ami other 

 improvements. It has also been proposed to use 

 these 6-inch maps as a record of sales or encum- 

 brances of land, thus lessening the cost and simpli- 

 fying the transfer of property. On the other hand, 

 their size unfits them for m'ost of the purposes for 

 which the 1-inch map is useful, and the contour 

 lines give a far less vivid and correct impression of 

 the physical features of a country than the hill 

 sketching of the 1-inch map. Most of the pur- 

 poses of the 6- inch plans are attained in r. still 

 more perfect manner from the 25-inch plans r 

 cadastral survey. This last name is taken from 

 the French cadastre ( 'a register of lands '), and is 

 defined (in the Recucil de* Lou, &c. ) as a plan 

 from which the area of land may be computed, 

 and from which its revenue may i valued. The 

 purposes to which these large plans may be applied 

 are as estate plans, for managing, draining, and 

 otherwise improving land, for facilitating its trans- 

 fer by registering sales or encumbrances ; and as 

 public maps, according to which local or general 

 taxes may be raised, and roads, railways, canals, 

 and other public works laid out and executed. In 

 1870 the Ordnance Survey was transferred from the 

 control of the War Office to that of the Office of 

 Works, and in 1890 to the newly-instituted Board 

 of Agriculture. 



Nearly all civilised states have produced trigono- 

 metricaf surveys, many of them of great excellence 

 as scientific works. I'he most important are : 



Austria, TI J nn or -8447 Inches to a mile. 

 Belgium, f BAo n or 3*168 Indies to m mile. 

 Denmark, ,4r.n or -792 inches to a mile. 

 France, ,(, or -792 Inches to a mile, and a reduced map, 



mnVo-i or '1267 inches to a mile. 

 Germany, m-Aiun or -0336 inches to a mile ; also uses or S 531 



inches to a mile. 

 Italy, uaon or 2-034 inches to a mile ; also lg gSuiii or CS30 



inches to a mile. 



Netherlands, ,),,, or 1-267 Inchen to a mile. 

 Norway and Sweden, )'> or -168 inches to a mile. 

 Switzerland. ,,! or 8 ft4 inches to a mile. 

 United States, from T-J'TIO or '6 Inches to a mile, to nfm 



or -*2 Inches to a mile. 



The Coast and Geodetic Survey of the United 

 States, which was authorised in 1807, but not 

 really begun till 1817, is a work of enormous ex- 

 tent, great accuracy, and minute detail. The full 

 organisation of the survey was mainly due to A. D. 

 llaclie i i|.v. i. The general charts are published on 

 a scale of -euJn-j or {ths of an inch to a mile ; the 

 harbours and ports 5 -i J-jn or 3J of an inch to a mile. 

 A vastly greater undertaking, the triangiilation of 

 the whole area of the republic, has been more 

 recently begun. The great Trigonometrical Survey 

 of India was commenced in 1832; and the year 

 1880-81 witnessed the completion of the principal 

 triangulation of all India. The maps are published 

 on various scales, those of the Trigonometrical 

 Survey being on a scale of rij'ji-i, or "25 inches to 

 a mile, whilst maps on both larger and smaller 

 scales are published for revenue and special pur- 



POM'S. 



The Geological Survey of the United Kingdom, 

 though under a different department of government 

 (Science and Art), may be shortly noticed here. 

 The English survey, l*gun in 1832. was completed 

 on the scale of 1 inch to a mile (solid geology), and 

 the Drift survey proceeded with. The Irish survey 

 was l>egun in 1840, but was subsequently suspended 

 till 1846. It was completed in 1887, and the whole 

 of the maps arc now published. In 1864 the survey 

 was extended to Scotland. The southern half of the 

 country has been completed, and the mapping of 

 the Highlands is now in progress. The surveys 



