NATURE 



361 



THURSDAY, FEBRUARY 14, 1889. 



ALPINE PHYSIOGRAPHY. 

 Die Gletscher der Ostalpcn. Von Dr. Eduard Richter. 

 Mit sieben Karten, zwei Ansichten, und vierundvierzig 

 Profilen im Text. (Stuttgart : J. Engelhorn, 1888.) 

 The Alps. By Prof. F. Umlauft, Ph.D. Translated by 

 Louisa Brough. With no Illustrations. (London: 

 Kegan Paul, Trench, and Co., 1889.) 



THE first of these two works— an elaborate memoir 

 of 306 pages — forms the third volume of the 

 " Handbiicher zur Deutschen Landes- und Volkskunde," 

 issued by the Centralkommission fiir wissenschaftliche 

 Landeskunde von Deutschland. About one-sixth of 

 the whole is occupied by some preliminary remarks, 

 and a discussion of the snow-line and the methods of 

 estimating it. As the author points out, this expression 

 is a rather vague one, and in a later part of the book 

 he indicates that it may be or has been used in four 

 different senses : (i) the lower limit of the patches of 

 firn or. n^ve, which chiefly depends on the steepness and 

 ruggedness of the mountains ; (2) the lower limit of the 

 connected permanent fields of snow and ice, excluding 

 the glaciers which descend from them, which may be 

 called the practical snow-line, — this depends mainly on 

 the nature of a declivity and its aspect ; (3) the " climatic '' 

 snow-line, a theoretical estimate of the snow-line arrived 

 at by considering climatic factors only ; (4) the normal 

 snow-covering, estimated by the line up to which the 

 snow melts away from the mountains. In proportion as 

 the mountains become regular in form, the first, second, 

 and fourth approach one another, and tend to coincide 

 with the third, and all must be considered in arriving at 

 a general estimation of the snow-line for any mountain 

 group. 



The author then passes in review the various districts 

 of the Eastern Alps, and enters into details as to the 

 distribution, arrangement, levels, and limits of the snow- 

 fields and glaciers. In this section of the work a large 

 amount of statistical information is collected, which, 

 together with the references to the literature, cannot fail 

 to be of much value to anyone engaged upon questions 

 relating to climate, and especially investigations bearing 

 upon glacial geology. 



In the concluding part of the work the author gives a 

 summary of the conclusions which follow from the fore- 

 going collection of facts. These are rendered more readily 

 intelligible by means of a map. A short description of 

 this will perhaps be the simplest way of indicating the 

 general results at which the author has arrived. As its 

 scale is comparatively small, details of mountain topo- 

 graphy are omitted for the sake of distinctness ; but the 

 chief river courses are clearly shown, and the boundary 

 between the mountain and lowland regions, north and 

 south, is indicated by a thin dotted line. But all the ground 

 above the 2600 metres contour-line (a very rough mean 

 for the snow-line of the whole region) is shaded. Thus 

 treated, we may remark in passing, the map gives an 

 excellent idea of what would be the structure of a group 

 of islands produced by the submergence of a mountain 

 Vol. XXXIX.— No. 1007. 



region, and a comparison of it with a map of the Lofoten 

 Islands, or indeed with many parts of the Scandinavian 

 and even North British coasts, is not without interest. 

 The " isochional " levels, as perhaps they might be called, 

 are indicated by a series of dotted lines, these being 

 graduated in hundreds of metres, the zones included 

 between them having the snow-line at heights differing 

 by this amount. Obviously, this is only a rough repre- 

 sentation of the facts, because, as the author carefully 

 points out, there are numerous minor variations, even in 

 one and the same district, due to the form or composition 

 of the mountains, the aspect of the slope, and the like. 



In the zone of 2500 metres, only a small portion of the 

 Eastern Alps is included, viz. the higher summits of the 

 northern limestone zone, such as the Zugspitz and the 

 Dachstein. The southern limit of this district trends 

 slightly north of east. The line limiting the zone of 2600 

 metres on the western side runs a little south of Landeck 

 and Innsbruck, and so does not include any important 

 summit ; but east of the Brenner it has a rather southerly 

 trend, and practically passes along the crest of the Hohe 

 Tauern. The limit of the zone of 2700 metres runs 

 roughly parallel with the last, till at the Glockner group 

 it turns sharply to the' south, and then, bending back, it 

 passes to the south of the Adamello group. Thus the 

 Brenta Alta group, the Marmolata and other peaks of the 

 South Tyrol Dolomites, are in the 2700 metres zone, though 

 a few summits of the Julian Alps, at the extreme east of the 

 map, are marked 2600 metres. There is yet one other 

 contour-line — that including the region where the snow- 

 line is at 2900 metres or even more. This is rudely 

 elliptical in shape, and includes the greater part of the 

 Bernina, Ortler, and Oetzthal groups, together with many 

 of the peaks on the left bank of the Upper Innthal. It 

 is thus obvious that the snow-line is not wholly dependent 

 on mountain form, or disposition, or on general tempera- 

 ture. The Adamello stands well to the south of the Oetz- 

 thal, yet its snow-line is full 100 metres lower. The 

 northern part of the Oetzthal is only a very little south of 

 the Glockner, yet the snow-line in the one district is 200 

 metres higher than in the other. But the configuration of 

 the Oetzthal group is, if anything, more favourable to the 

 accumulation of snow, and one would have expected, at 

 first sight, to find the difference incline in the other direc- 

 tion. It is, then, evident that other climatic factors are of 

 great importance, not the least of these being the amount 

 of precipitation during the winter months. On this 

 subject some interesting evidence is adduced. 



The book is in clear good type, and the maps and 

 sections at the end are printed with a blank space, equal 

 to a page, on the inner side, so that they can be kept in 

 sight when the book is read — a very convenient arrange- 

 ment too often neglected. Most of the illustrations in the 

 text are only diagrammatic sections, but the two " views " 

 of the Gaisberg Glacier and of the Marmolata Glacier 

 are excellent of their kind. The former is really no more 

 than a " pen-and-ink sketch," yet it gives a very good idea 

 of an Alpine view, and is far better than the wretched 

 caricatures of mountain scenery which too often do duty 

 in English scientific text-books. It may be commended 

 to our publishers. 



The second volume before us is one larger in size, 

 characterized in parts by the same laborious minuteness 



K 



