March 27, 18 90 J 



NATURE 



483 



classes should be carried on so that the Government 

 ^rant be earned," is a nott sequitur; at all events until the 

 Science and Art Department award grants for distinctively- 

 technical subjects under the new Technical Instruction 

 Act. 



We cannot help thinking that if due weight is allowed 

 to these considerations the estimate of 15^-. a head will be 

 largely raised (unless compensation be sought by cutting 

 down some of the more expensive trade classes) ; and as 

 we suppose the endowment cannot be much increased, 

 the number of students to be provided for must be 

 necessarily diminished. In fact, the whole scale on 

 which Mr. Plumbe has calculated the requirements of 

 the Institute may have to be somewhat revised. To 

 those who consider large numbers all-important, this may 

 seem deplorable, but we are convinced that the Com- 

 mittee of the South London Polytechnic will prefer the 

 interests of efficiency to those of temporary display. 



One other matter which we notice with some sur- 

 prise and regret is the apparent omission in the plans 

 to provide committee-rooms and other accommodation 

 which can be utilized by local working men's organiza- 

 tions. We referred in our former article to the importance 

 of making the Institutes real working-class centres, and 

 the reply of the Charity Commissioners to the deputation 

 from the London Trades Council on the subject was 

 supposed to be favourable to the provision in connection 

 with each Institute of rooms which could be utilized on 

 moderate payment by various working-class societies 

 which now too often have to meet in public-houses. The 

 omission of any such provision in the plans for Battersea 

 is a serious blemish on the scheme, which, however, can 

 easily be corrected, as soon as pointed out. 



The Committee will have a great opportunity, which it 

 is to be hoped they will use aright, of providing the in- 

 habitants of South London with a technical and recreative 

 Institute, which in its close adaptation to local needs may 

 serve as model for all such Institutes in the future. 



A GEOLOGICAL MAP OF THE ALPINE CHAIN. 



Geologische Ubersichtskarte der Alpen. Entworfen von 

 Dr. Franz Noe. Mit einem Begleitworte. (Wien : Ed. 

 Holzel, 1890.) 



GOOD, and in some cases even elaborate, geological 

 maps exist for parts of the Alps ; but one to exhibit 

 the chain as a whole, without being on a scale so large as 

 to be unwieldy or so small as to be indistinct, has been 

 hitherto a desideratum. This has now been supplied by 

 Dr. Noe. The scale adopted is i in 1,000,000, or about 

 16 miles to the inch, which very well satisfies both the 

 above conditions. A glance at the list of authorities 

 which have been consulted indicates that Dr. Noe has 

 had no easy task ; for in Alpine geology there are indeed 

 consellors enough, but their multitude is not strength, for 

 they are so often at variance. 



At the present stage of knowledge, the chartographer 

 must be content, in dealing with the crystalline schists 

 (using that term in a rather wide sense), to colour his map 

 petrographically — that is to say, he must, as far as possible, 

 record facts and avoid theories. Dr. Noe has endea- 

 voured, though not with complete success, to render his 

 maps petrographical in the parts where doubt might arise, 



viz. those occupied by that crystalline series which, 

 whatever may be its age, in the Alps always underlies 

 any sedimentary rock to which a date can be assigned. 

 The principle of coloration agrees very nearly with that 

 suggested by the International Geological Congress at 

 Bologna. Crimson denotes the deep-seated igneous rocks 

 of the more acid type, dull green the more basic ; 

 two slightly different shades of red represent respectively 

 the older (and in most cases more acid) volcanics and the 

 newer volcanics. Four colours are employed to express 

 the " crystalline schist" series : one, for the Central gneiss 

 and some of the oldest mica-schists ; another, for the less 

 coarsely crystalline (and probably newer) mica-schists, 

 together with calc-schists, chlorite-schists, &c. ; a third, 

 for certain crystalline schists, phyllite;, and clay-slates 

 of uncertain geological age ; and marbles are indicated 

 by a deep blue. Palaeozoic rocks (exclusive of Permian) 

 are coloured purple, the different series being distin- 

 guished by symbols ; pale brown denotes Permian ; tints 

 of blue represent the Triassic and Jurassic strata ; green 

 signifies Neocomian and Cretaceous ; orange the older 

 Tertiary, flysch having a separate tint ; one shade of 

 yellow is used for Miocene and Pliocene ; another for 

 Diluvial and Alluvial deposits — the former a word of 

 misleading origin, which ought to have long since disap- 

 peared from geological nomenclature. 



Very wisely, Dr. Noe has included in his map some- 

 thing more than the Alps. Not only do we find the 

 Jura, but also this region is extended far enough in the 

 direction of Dole to exhibit the remarkable exposure 

 of the old crystalline floor, north of that town. 

 On the right bank of the Rhine, in the neighbourhood^ 

 of Sackingen, a considerable strip of crystalline rock is 

 shown, the end of the great Schwarzwald massif; and 

 north of the Eastern Alps we find the crystalline rocks 

 indicated as they uprise from beneath the Miocene on the 

 left bank of the Danube, as, for example, near Linz, and 

 again at Pressburg. The geological colours also are 

 carried down the east coast of the Adriatic as far as 

 Spalato, so that the connection of the Istrian and Dal- 

 matian Alps with the main chain is made perfectly clear. 

 Unfortunately, however, Dr. Noe has not applied the same 

 treatment to the Apennines, though their connection with 

 the Alpine chain cannot be of less geological importance, 

 for he brings the colours to an abrupt end a few miles 

 west of Savona. 



In one or two respects the above system of coloration 

 seems open to criticism. The tint and the lines used to 

 indicate mountain land are productive of some confusion, 

 and increase the difficulty of identifying the colours, with- 

 out, as we think, producing a compensating advantage. 

 The use of three colours for the Trias-Rhaetic seems a 

 disproportionate subdivision when only one is allotted 

 to Neocomian-Cretaceous. We are, however, disposed 

 to differ more seriously — though only occasionally— from 

 Dr. Noe as to his use of the colours for the divisions of the 

 crystalline schists. One of these is made too inclusive, 

 because it is applied to clay-slates and phyllites as well as 

 to rocks which must be admitted to be crystalline schists. 

 Granted that there is sometimes a difficulty in separating 

 these in the field, we fail to see the propriety of deli- 

 berately effacing the distinction. Fortunately, however, 

 this confusion, owing to the scale of the map, does not 



