September 17, 1908] 



NA TURE 



497 



Government of this country. Let it not be thought, how- 

 ever, that while we for the moment pay little atlention 

 to the regions lying outside this definition, we are sup- 

 porting the fallacious idea that the survey of any part of 

 the earth can be considered apart from the survey of the 

 surrounding country. With the possible exception of I he 

 case of an oceanic island such an assumption would be 

 an erroneous one. Our British empire is so widespread and 

 our possessions are so often in close and intricate ju.xta- 

 position with those of other nations that there is in this 

 work large scope, and indeed necessity, for international 

 co-operation. Examples of this will occur to us in the 

 course of our review. We shall thus see that in addition 

 to the obvious connection which the geography of our 

 empire has with that of other countries there is an even 

 closer connection in the methods of manufacture of that 

 geography, which methods we summarise under the general 

 term of survey. One of the root ambitions of the scientific 

 surveyor is to determine the exact figure of the earth, an 

 operation for which observations spreading over a largr- 

 area of the earth's surface are deinanded. In fact, we 

 may truly say that the problem of the earth's shape will 

 not be completely solved until the whole surface is known 

 to the surveyor. That is, therefore, pre-eminently a problem 

 for international solution. 



Before proceeding to the consideration of our special 

 subject, the survey of the British empire, it will be interest- 

 ing to interpose a few remarks on the questions of Iho 

 utility and origin of national surveys in general. We may 

 first note the somewhat curious fact that the production ol 

 a map of a country, useful as such a work is for many 

 purposes, has almost always been embarked upon because 

 the imperative necessity of maps of the theatre of opera- 

 lions in war has been brought home to the people and 

 Government of a nation. Thus the ordnance survey of 

 England had its first beginning in a military map ot thi 

 highlands of Scotland, cotnmenced in 1747, intended to 

 facilitate the operations of the troops under the command 

 of the Duke of Cumberland. It was not until many years 

 later that the systematic triangulation of the country w.is 

 undertaken, a work which was initiated partly for map 

 making and partly for astronomical purposes. There was 

 a consensus of opinion among astronomers that it would 

 be greatly to the advantage of that science if the observa- 

 tories of Greenwich and Paris could be connected by 

 triangulation, and the famous French astronomer Cassini, 

 in October, 1783, drew up a memoir to this effect. The 

 arguments brought forward convinced King George 111., 

 and he granted a sum of money sufficient to enable the 

 work to be started. This act of royal generosity was 

 recorded by the surveyors in the following grateful terms : 

 " \ generous and beneficent monarch, whose know-ledge 

 and love of the sciences arc sufficiently evidenced by the 

 protection which he constantly affords' them and under 

 whose auspices they are daily seen to flourish, soon supplied 

 the funds that were judged necessary. What his Majesty 

 has been pleased to give so liberally it is our duty to 

 manage with frugality consistent with the best possible 

 execution of the business to be done." 



It is worthy of remark that the junction of the 

 triangulation systems of Great Britain and France was not 

 made until 1861, and that the trigonometrical connection 

 of Greenwich and Paris observatories has not vet been 

 completed to the final satisfaction of men of science, a point 

 which we shall have occasion to recur to later. 



In France, we may note in passing, the starting of the 

 triangulation had a quite different and quite definite object, 

 the determination of the length of the metre. This un- 

 scientific unit of length was fixed as a fraction (r/ 10,000,000) 

 of the quadrant of the earth's surface between the Pole 

 and the Equator, and to find this quantity it was necessarv 

 to measure on the earth's surface as long an arc of the 

 meridian as could be obtained. 



In the case of our other great national survey, that of 

 India, its origin is to be found in circumstances somewhat 

 analogous. The Madras Government, owing to the success 

 of the British arms in the .Mysore campaign, found itself 

 with a great accession of totally unsurveyed country in the 

 middle of the Peninsula, w-hile at the same tirrie there 

 were only in existence the roughest sketch-maps of the 

 older possessions. It was apparent that if any map. of 



NO. 2029, VOL. 78] 



even approximate accuracy, was to be made covering a 

 country of such vast area, it was imperative that the work 

 should be prosecuted upon the most rigorous and strictly 

 scientific basis. The general lines upon which it should be 

 undertaken were laid dowm in February, 1800, by Brigade- 

 Major Lambton, who addressed a letter to the Madras 

 Government advocating a mathematical and geographical 

 survey of the peninsula. 



In this letter he discussed the principles upon which such 

 a survey should be based. He dismissed astronomical fixa- 

 tions as not providing the requisite degree of precision, 

 observing that such determinations of position are liable to 

 great inaccuracies, " three, four, perhaps ten minutes," and 

 proposed a triangulation emanating from a measured base 

 line checked by similar base lines at intervals. He recog- 

 nised that the figure of the earth and lengths of the polar 

 and equatorial radii were not then known with the precision 

 necessary for fixing the spheroidal co-ordinates of the trigo- 

 nometrical stations of a survey covering such a large area 

 of the earth's surface, and that a geodetic survey was 

 therefore necessary pari passu with the geographical survey. 

 He had an impression, how derived it is not now possible 

 to say, that there was a sudden abnormal diminution of 

 the force of gravity at the latitude of 10° north, and con- 

 sequently that " a degree on the meridian from that parallel 

 to the Equator must be very short compared with a 

 degree to the northward of 10°. " He observed that it 

 would be necessary to " attend to this circumstance," 

 w'hich he characterised as important both from the map- 

 making and from the rigorously scientific point of view. 

 He added : " I shall rejoice, indeed, if it should come within 

 my province to make observations tending to elucidate so 

 sublime a subject." 



In a similar case, occurring in recent years, the outcome 

 has not been so satisfactory. It will be within the recollec- 

 tion of all here how at the time of the South .'\frican war 

 the public at home learnt with shocked surprise that there 

 were no maps in existence of a colony which had been 

 under the British flag for a long period of years. To those 

 who knew the facts this was, naturally, no matter of 

 surprise ; but it was earnestly hoped by many that this 

 grave deficiency thus revealed by the stress of war would 

 be remedied by quiet work in the time of peace, and that, 

 at the conclusion of the military operations, the foundation 

 should be laid for a federal survey department of British 

 South -Africa comparable with, though on a more moderate 

 scale than, the Survey Department of India. This hopeful 

 scheme, which it may be recorded very nearly came to 

 fruition, ultimately found political conditions too adverse, 

 and had to be indefinitely postponed. An army engaged in 

 field operations in the north of Natal now, or, in fact, at 

 any time for an indefinite number of years in the future, 

 would find the country nearly as mapless as it was found 

 by Sir R. BuUer in 1900. 



In this short recital of the determining causes which 

 have in the past led to the initiation of national surveys, 

 it will have been noticed that no allusion has been made 

 to what we should now perhaps consider the main utility 

 of a map — namely, its value for all purposes connected 

 with the ownership, development, and taxation of land. 

 When the ordnance surveys of Great Britain and Ireland 

 were originated there was little thought of this use, and 

 it was not until long after that period, w^hen the enormous 

 deficiencies of the existing property plans were revealed 

 by the Tithe Commutation Acts and by the railway boom, 

 that the value of a national survey for preparing a 

 cadastral or large-scale property map of the country was 

 recognised and acted upon. Now this is often the 

 ostensible object for embarking upon a regular survey. It 

 is fully recognised that, especially in the case of a country 

 undergoing rapid development, which is fortunately true 

 of many of our oversea possessions, the provision of an 

 accurate land map is of prime necessity both to the private 

 or corporate landowner and to the State. 



Neither were any of the early surveys undertaken for 

 the purpose of mutual delimitation of international 

 boundaries, a necessity which has in recent years been 

 the stimulating cause for many pieces of valuable survey 

 work, especially in Africa. 



The other manifold uses of a map are familiar to all 

 of you, and we need not pause to enumerate them. We 



