82 



NATURE 



[September ig, 1912 



tions of altitude it was arranged lliat contours should 

 be shown at vertical intervals of a hundred metres, 

 or at smaller intervals in the case of very flat, and 

 larger in the case of steep ground, the height being 

 measured from mean sea-level, as determined in the 

 case of each country ; while the levels of the surface 

 of the country were to be indicated by a scale of colour 

 tints, the colours being green from o to 300 metres, 

 brown from 300 to 2500 metres, and purple above 

 2500 metres. In the same manner the depths of the 

 ocean and of large lakes were to be indicated by 

 varying tints of blue, so as to show intervals of 100 

 metres. In order to ensure uniformity in the scale 

 of colours to be used, a copv of it, as approved by the 

 committee, was included in the plate of topographical 

 symbols. 



The whole scheme was thoroughly well worked out, 

 and great credit is due to the members of the inter- 

 national committee for the manner in which they car- 

 ried out their difficult task. Since the meeting of the 

 committee in 1909 the preparation of the sheets, in 

 accordance with the principles decided upon, has been 

 taken in hand in several countries, and a number of 

 these have been issued, which give a good idea of 

 what this great map, the largest ever contemplated, 

 will be like. These sheets deserve to be carefully 

 studied, and will doubtless be the subject of consider- 

 able criticism, as there are several points which seem 

 worthy of examination. 



In the first place, it is for consideration whether 

 it would not have , been better if the colour scheme 

 for representing differences of altitude had been 

 omitted, as it is doubtful whether the advantage of 

 the result gained is commensurate with the increased 

 cost of printing the colours. And one naturally asks 

 for what purpose is the map intended. Is it for the 

 use of skilled geographers, of whom there are a com- 

 paratively small number in each country, or is it for 

 the instruction of ordinary people? If it is for the 

 latter, it is to be feared that the colour scheme will 

 give rise to erroneous impressions. Compare, for 

 example, sheet North, M 31, of France, with sheet 

 South, H 34, of part of South Africa. In the former, 

 as the greater part of the country shown is less than 

 300 metres above the sea, the general colour of the 

 sheet is green, while in the latter, as nearly the whole 

 of the country included has an altitude of more than 

 300 metres, the map is for the most part brown. This 

 to the less educated man will probably convey the 

 idea that, while France is a fertile country. South 

 Africa is a desert. The fact, too, that the darker tint 

 of green represents the lower level and the lighter 

 the higher, while, in the case of the brown, the lighter 

 represents the lower and the darker the higher, ancl, 

 in the case of the purple, the relative strength of the 

 tints is again reversed, is rather confusing. 



There is another point as regards the colour scheme 

 which might be noticed, that is, that it is not the 

 same on different sheets. For example, the scale of 

 tints adopted in sheet North, O 30 (Scotland), North, 

 M 31 (F" ranee), and North, K 35 (Turkey), do not 

 correspond. In the Scotch map the brown colour 

 commences at an altitude of 200 metres,' in the French 

 at 300 metres, and in the Turkish at 400 metres. 

 There may be some reason for this, but it appears not 

 to be in accord with the resolutions of the committee. 

 Another reason for omitting the colour scheme for 

 altitudes is that it might be better to keep colour 

 work for other purposes, such as indicating political 

 divisions, as there can be little doubt that so good a 

 map as this, when completed, will be largely used for 

 many purposes. It might be better that on a map 

 of this small scale only the horizontal features, such 

 as coast lines, river courses, railways, roads, and the 



NO. 2238. VOL. 90] 



position of towns should be shown, while to represent 

 height graphically tends to obscure the former. 



Another criticism I would venture to make is that 

 the resolutions of the committee appear to have been 

 drawn up on the supposition that thr whole world 

 has been accurately surveyed, and no .ittempt seems 

 to have been made to distinguish between those re- 

 gions of which the maps are based on triangulation, 

 such as England and parts of Europe, and the coun- 

 tries of which complete surveys have not yet been 

 made. As the construction of the map proceeds and 

 sheets are prepared of parts of the world our know- 

 ledge of which is imperfect, this want will become 

 more pressing, but it is noticeable even with regard 

 to the sheets already published. It is one of the evils 

 of cartography that where anything is shown on a 

 carefully engraved map it comes to be regarded as 

 true, and, if it afterwards turns out to be erroneous, 

 it is not easy to get it altered. 



The scale of the map, i/ioooooo, appears to have 

 been wisely chosen, as it is sufficiently large to give 

 an adequate amount of detail, while, at the same 

 time, the sheets will not be unduly numerous. Of 

 course, for an international map a cadastral scale 

 was essential, although for national maps a scale 

 based upon the national system of measures is more 

 convenient, as, for example, in the United Kingdom, 

 where the scale of one inch and six inches to the mile 

 are better than scales of 1/50000 and i/ioooo would 

 have been. They are more suited for the majority 

 of individuals, and an ordinary foot-rule can be used 

 for measuring distances, instead of having to take 

 them off with a pair of dividers from the printed scale 

 on the map. 



Looked at from the general point of view, there can 

 be no doubt that the international map is a most 

 important and valuable undertaking. It is satisfac- 

 tory that such a leading part in the matter has been 

 taken by the British officers of the Royal Engineers 

 and by the Royal Geographical Society. 



In speaking of this map, I have referred to the 

 advisability, if not the necessity, of distinguishing 

 between what is accurately and what is inaccurately 

 known, and this brings me to another matter of 

 considerable interest, the preparation of maps based 

 upon the observations and information collected by 

 explorers in unknown or little known countries. To 

 these explorers, some of whom have not been trained 

 in geographical science, a large amount of detail 

 shown upon modern maps is due, and it is only a 

 small proportion of the land surface of the globe 

 that has, up to the present, been surveyed in a 

 scientific manner. 



It is therefore of the greatest importance that the 

 best value possible should be obtained from the work 

 done by explorers, and this in the past has not always 

 been sufficiently attended to, though during the last 

 few years it is better understood. The people who 

 stop at home in comfortable ease do not sufficiently 

 realise the difficulties under which the conscientious 

 traveller works and gathers together information 

 about the country he passes through. Formerly, he 

 generally had to work out his own observations and 

 compile ,his own maps, but now conditions in this 

 respect have greatly improved, and when he brings 

 home his observations, notes, and sketches he can 

 hand them over to some body, such as the Royal 

 Geographical Society, by whom they will be put in 

 shape in a better manner than he could do it for 

 himself. One has heard of an explorer in a little- 

 known country sitting up all night after a hard day's 

 work, working out his astronomical observations, and 

 trying to put his rough surveys into shape. He would 

 have done better to have gone to sleep and prepared 



