September 2^, 1915] 



NATURE 



105 



mena which should be observed in the type of region 

 which he is traversing, nor can he read the geo- 

 graphical evidence which lies patent to a trained 

 observer at every point of the journey ; much, there- 

 fore, of what he records may be of interest, but prob- 

 ably lacks data which are essential to the geographer 

 if he is to understand the geographical character of 

 the region, and utilise it properly. 



Thus it happens that although the amount of geo- 

 graphical material which is being garnered may be 

 large, the proportion of it which is available for use 

 in a scientific investigation of an area is smaller than 

 is probably realised by those who have not made the 

 experiment. And yet it is only by this scientific investi- 

 gation of selected localities or of a single phenomenon 

 and by working them out as thoroughly as possible 

 that any real advance in geographical science can be 

 made. There should now be an ever-increasing num- 

 ber of geographers trained to proceed in their 

 investigations by the true scientific method, and there 

 should be a very considerable amount of sound work 

 in various branches of the subject which aims at 

 thoroughly investigating some phenomenon, or group 

 of phenomena, so as to present a grouping of data, 

 carefully verified and critically discussed, in order to 

 arrive at conclusions which may form a useful addi- 

 tion, however small, to the sum of our geographical 

 knowledge. 



So far as I am able to judge, the output of serious 

 work of this character is not nearly as large as it 

 should be, and I would indicate some fields in which 

 fhere is a lack of individual work of this character. 

 Until more of it is undertaken we shall lack in this 

 country the material from which the foundations of 

 scientific geography can be built up, and while our 

 own islands and the various parts of the British Em- 

 pire furnish unrivalled opportunities for such work, 

 there are still far too many subjects where the most 

 thorough investigations have been made in other 

 countries. 



Mathematical geography presents a field for re- 

 search which has had comparatively little attention 

 paid to it in this country. In many respects this part 

 of the subject is peculiarly suitable for such treatment, 

 since it admits of the employment of precise methods 

 to an extent which is not always practicable in cases 

 where so many of the factors can only be approxi- 

 mately defined. The determination of positions on 

 the earth's surface is carried to great refinement in 

 the national surveys of most civilised countries in 

 order to furnish the necessary controls for the pre- 

 paration of large-scale maps, but when we pass to 

 the location of travellers' routes, where considerable 

 allowance has to be made for the conditions under 

 which the observations have to be taken, we find 

 that very inadequate attention is usually paid to the 

 discussion of the results. Usually a mean value for 

 each latitude, longitude, or azimuth is obtained by the 

 computer, and he remains satisfied with this, so that 

 when the route of another traveller follows the same 

 line or crosses it at one or more points, it is almost 

 impossible for the cartographer to say which of the 

 two determinations of any position is entitled to the 

 greater confidence. In this class of work, whether 

 the results are obtained from absolute observations at 

 certain points or from the direction of march, and the 

 distance traversed, it is quite practicable to determine 

 the range of uncertainty within which the positions 

 of different points are laid down, and it is eminently 

 desirable that this should always be done in order 

 that the results of various routes which may inter- 

 sect in partially known regions may be adjusted 

 in accordance with definite mathematical processes. 

 Some important expeditions on which infinite labour 

 NO. 2395, VOL. 96] 



and considerable sums have been expended have pre- 

 sented their results, in so far as they relate to the 

 routes which have been followed and the position of 

 points which have been determined, in such a way 

 that it is impossible to say with what precision such 

 positions have been determined, and consequently any 

 combination of these results with those of later ex- 

 peditions has to be carried out empirically, since 

 adequate data are no longer available for the employ- 

 ment of better and more scientific methods. 



This crude and unsatisfactory w^ay of treating 

 observations, which in many cases have been obtained 

 under conditions of the greatest difficulty and even 

 hardship, is largely due to the lack of interest which 

 geographers have shown in this part of their subject. 

 Methods of observation and methods of computation 

 are rarely discussed before any of our geographical 

 societies or in any of our publications, and it is only 

 by such discussions that the importance of properly 

 working out the available material at a time when 

 the observer can be consulted on points which are 

 doubtful, or where further explanation is desirable, 

 becomes generally appreciated. 



No set of physical or astronomical observations is 

 ever discussed or even presented without the degree 

 of precision or trustworthiness being definitely stated ; 

 yet in geography this sound rule is too often 

 neglected. 



There are several regions where travellers' routes 

 intersect which should provide ample material for the 

 careful reduction and adjustment of the results. I 

 fear, however, that there would be great difficulty in 

 obtaining the original observations which are indis- 

 pensable in such an investigation, and in the interest 

 of research it is highly desirable that the original 

 documents of all work of importance should be pre- 

 served and the place where they may be consulted 

 should be recorded in the published account. 



There is room in the geographical investigation of 

 sea and land, even within the limits of the British 

 Empire, for the employment of methods of observation 

 and computation of the highest precision as well as 

 of the simpler and more approximate kinds, but 

 everyone who presents the results of his work should 

 deem it his first duty to state explicitly the methods 

 which he employed, and the accuracy to which he 

 attained, in such a form that all who make use of 

 them can judge for themselves of the degree of their 

 trustworthiness. 



In such work, while the instruments used are of 

 great importance, too often the briefest description, 

 such as "a 4-in. theodolite," is deemed sufficient. If 

 the observer wishes his work to be treated seriously 

 as a definite contribution to science we require to 

 know more than this, and a clear account of the 

 essentials of the instrument, a statement of its errors, 

 and of the methods of observation adopted are the 

 least that will suffice. The account of anv expedition 

 should treat so fully of the instruments, observations, 

 and computations utilised to determine the positions 

 of places visited that anyone can re-examine the 

 evidence and form his opinion on the value of the 

 results obtained. A mere tabular statement of 

 accepted values, which frequentlv is all that is pro- 

 vided, is of small value from a scientific point of view. 

 Probablv one reason for this state of thinjrs is that 

 too little attention is beine paid bv geographers to 

 their instruments. Theodolites, levels, compasses, 

 clinometers, tarheometers, plane-tables, pantographs, 

 co-ordinatogranhs, planimeters, and the many other 

 instruments which are used by the surveyor, the carto- 

 e^rapher, the computer, have in no case arrived at a 

 final state of perfection, but it is seldom that we find 

 a critical description of an instrument in our journals. 



