t26 



NA TURE 



[Septembi^r 9, 1909 



can be inserted without overcrowding, or conversely, if 

 the scale is fixed, the amount of detail and method of 

 showing it should be such as to avoid the common fault 

 of ovei crowding the map. 



In pupulous countries, such as Belgium, France, and 

 Germany, where buildings, roads, railways, &c., are 

 nujnerous, a larger scale is, caetcris paribus, desirable, 

 than in less populous countries. 



-All important detail such as roads, railways, canals, 

 forests, woods, &c., should appear on the map, as should 

 the more important names, but it is a matter for con- 

 sideration how far minor detail such as orchards, marshes, 

 rough pasture, stale of cultivation, &c., should be inserted 

 on the map, and to what extent the less important names 

 should be omitted. 



In hilly country hachures and contours, especially if in 

 black, tend to obscure the detail and names, and the 

 smaller the scale the greater this tendency. 



Methods of reproduction will be dealt with later, but I 

 may here say that more detail and names can be shown 

 clearly on a given scale if the map is engraved on copper 

 than if reproduced in any other way. The scales adopted 

 by different countries vary very much — I give below the 

 scales adopted by some of the principal surveys. 



-i^iitTs scale — Switzerland (the more populous parts), 

 Prussia, Baden, .Saxony, Bavaria, and Wurtemberg (these 

 German maps, although called maps of position, are prac- 

 tically topographical). 



T O 1)0 scale — Belgium and Denmark. 



rc^TTi? scale — France (the new topographical map), 

 Algeria, Tunis, Holland, Japan, Spain, Switzerland (the 

 less populous parts). 



jTrljjif scale — the United States (the more populous parts). 



eaTTTF scale (i inch to a mile) — Great Britain and Ireland, 

 and Canada. 



Tsiim scale — the Austrian Empire. 



iriniiro scale — the old start map of France. 



Tuo'sDiT scale — the German Empire, Italy, Norway, 

 Portugal, Sweden, and Switzerland (Dufour atlas). 



TiTBuTT scale — the United States (the less populous parts). 



1 isVuff scale — Russia. 



jso'cTiB scale — the United States (barren districts). 



The introduction of cycles, motors, and other rapid 

 means of locomotion has led to a demand for a scale which 

 will show a considerable tract of country on a sheet of 

 moderate size. If the standard map is already on rather 

 a large scale, this demand is best met by publishing a 

 reduction of the standard map. This course is followed 

 by Great Britain and Ireland and by Canada, the i-inch 

 map of which is reduced to and published on the i-inch 

 scale ; but if only one scale is used a compromise must be 

 arrived at which will meet the reasonable requirements 

 of rapid locomotion, as well as the other essentials of a 

 topographical map. 



If I may venture an opinion in a matter in which prac- 

 tice varies so much, it is that for countries using British 

 measures in which, owing to dense population, the detail 

 is close the i-inch scale (Tnjiirjr) is a very good one, and 

 that for more open parts the J-inch scale may with 

 advantage be adopted. For countries using metrical 

 measures I should advocate .t^Jjitt and vs-sVire respectively. 

 These scales do not difTer largely from those adopted by 

 most of the principal countries, the majoritv of which use 

 scales between sjmjdtt ^nd -nrTrnTrTr for fairly close countries. 



W'here it is important to keep the cost down I should 



advocate a half-inch to the mile or a t^Vtjtjtt scale. 



All 



except the most closely populated country can be shown 

 clearly on such scales provided the maps do not show too 

 many names or too much small detail. 



The United States have scales of Tniltrir, rsirirnTr. ^^^ 

 T>ToVTri[, the general closeness of detail in any area deter- 

 mining which of these three scales is adopted. This 

 arrangement is a good one, and would be still better if 

 the areas published on the nVjuir scale were also reduced 

 to and published on the t'-s'titfj scale, and if the whole 

 country were published on the TsisVirir scale. The principle 

 here advocated of having each scale so far as possilile 

 complete for the whole country has been carried out by 

 Great Britain, where the whole country, except some un- 

 cultivated areas, is published on the 25-inch i-lrs^•^ ) scale, 



NO. 2080, VOL. 81] 



and the whole country on the 6-inch, the i-inch, the J-inch, 

 the .i-inch, and other smaller scales. 



Scale of Field Survey. 



It is usual to make the field survey for small scale maps 

 on a larger scale than that on which the map is to be 

 published with the view of securing greater accuracy of 

 detail, but this should not be overdone. If the field survey 

 is on too large a scale it entails needless expense, also 

 when the surveyor is working on too large a scale he is 

 apt not to realise the effect of reduction on his survey, 

 and is Hkely to survey so much detail as to overcrowd the 

 map, thus increasing the cost of the work and injuring 

 the map. 



When the map is reproduced by photographic methods 

 the fair drawing is usually on a larger scale than the 

 finished map, so as to get finer results on reduction ; but 

 in this case also, for somewhat similar reasons to those 

 stated above, there are limits, to the amount of reduction 

 which can be made with advantage. 



In these respects the practice of different countries varies 

 considerably. 



In .\ustria the field survey is on the ^-sSbtt scale ; this 

 is reduced to and drawn on- the jurjjijr scale, and this draw- 

 ing is reproduced by heliogravure on the ^zivis scale. 



In France the field survey is on the x^cTiir or ^^hm scale. 

 The survey is reduced to and drawn on the TjrlrnF scale. 

 In Algeria and Tunis, both field survey and drawing are 

 on the jjiJrTTTT scale. In all cases the French maps are now 

 reproduced by heliogravure on the tfsuu scale from the 

 TiriTTVTT- ■^cale drawings. 



In Germany the field survey is on the TfsATrn scale. This 

 is reduced to the Ttnhv-ei on which scale the maps are 

 engraved on copper. 



In Great Britain the i-inch map is based on the 25-inch 

 and 6-inch survey. These were reduced, and ,a fair draw- 

 ing was made on the 2-inch scale in a manner suitable 

 for reduction to the i-inch scale — i.e. the detail lettering, 

 &c., were drawn so that when reduced to the i-inch scale 

 they should be in proper proportion. This drawing was 

 reduced and printed by heliozincography on the i-inch scale, 

 and from these prints was engraved on copper. 



In America the field surveys are on the scales of js-^oi 

 rslTRTi and TiTTiiTrir for the uirsTrrr'. the t'ttttttti and the -jrsVors- 

 scale maps respectively. The drawings, on the same 

 scale as the field survey, are reduced by photography and 

 engraved on copper. 



I consider that the best results are obtained when the 

 field survey is made on double the scale of the finished 

 map; that if reproduction is to be by engraving, the fair 

 drawing should be on the same scale as the finished map ; 

 that if, on the other hand, reproduction is to be by photo- 

 graphic methods, the fair drawing should be on the same 

 scale as the survey, i.e. double that of the finished map. 

 The reduction I advocate should conduce to accuracy of 

 detail and, if reproduced photographically, to fineness of 

 detail, while it is not so great that the surveyor and 

 draughtsman should be unable to realise the effect of 

 reduction. 



Detail. 



The need of considering the amount of detail. Sec, to 

 be shown is not ahvavs sufiiciently realised. The way in 

 which detail is to be represented also needs consideration, 

 as on small scale maps much detail has to be represented 

 conventionally. 



Railways have to be shown conventionally, and should 

 be so marked that thev catch the eye without being too 

 heavy. 



Roads also should be clearly marked. Where different 

 classes of roads exist thev should be distinctively shown, 

 main roads being more prominent than others. It is 

 important to know what roads are fit for fast wheeled 

 traffic in all weathers, and which are fit only for slow 

 traffic. The exact classification of roads must depend on 

 the conditions obtaining in the country. The most 

 elaborate classification is that shown on the French maps, 

 and next that shown on the maps of Great Britain. Pro- 

 vided that important distinctions are represented, the 

 simpler the classification the better. 



