150 Surface- Geology of Belgium. 



by a chromo -lithographic map, depicting the surface-geology of 

 Belgium, which, by the permission of the Council of the Eoyal 

 Agricultural Society, we are enabled to reproduce here, for the 

 illustration and better explanation of the few remarks we propose to 

 make thereon. 



The accompanying map (Plate V.) conveys to the eye the broad 

 features of the surface-geology of the country, and by the intro- 

 duction of a series of contour-lines and figures, giving the altitudes, 

 we ai-e enabled to see at a glance the extent of area which each for- 

 mation occupies, its elevation above the sea, and the coincidence of 

 these lines with the boundaries of the two gi-eat superficial deposits, 

 the 'Campine Sands' and the 'Limon de Hesbaye,' which together 

 form two-thirds of the surface of the country. The boundary of the 

 remaining third is sharply defined by the valley of the Mouse, south 

 of which is the plateau -region, mapped as consisting simply of 

 'strong-land,' the term being used to convey not the geological 

 nature of the tract, but its agricultural character, for we must re- 

 member that the map is intended to give a notion of the surface to 

 the farmer. Geologists know, and are reminded by Mr. Jenkins in 

 the text (p. 6), that "the highly contorted beds of limestone or 

 schist belonging to the Carboniferous, Devonian, and Silurian 

 periods," form the solid substrata of this region. 



The coincidence of the agricultural and physical characteristics 

 of the author's divisions of the kingdom are described in the 

 following paragraph (p. 2). " In Belgium there are four descriptions 

 of soil, and as many kinds of farming, each soil having a culture 

 peculiar to it. The distribution of the soils is shown on our map by 

 colours, which roughly represent by their hue the relative strength 

 of the land in different regions. Each of these regions is 

 characterised not only by its soil, subsoil, and mode of cultivation, 

 but also by a variation in climate and a difference in the form of its 

 surface, with the exception of the recently formed Polder-land, 

 which has the same climate and surface-configuration as the adjoining 

 districts. We may therefore regard these divisions as natural, and 

 as affording a most interesting example of the dependence of modes 

 of culture on natural attributes." 



These divisions are as follows (p. 3) : — "1. The sandy district of 

 Northern Belgium; 2. The loamy district of Central Belgium; 3. 

 The Polders and Eiver- valleys ; and 4. The plateau-region of 

 Southern Belgium. The tract of country at the extreme south of 

 Belgium, viz., the Bas Luxembourg, might have been distinguished 

 by another colour ; but as its extent is small, and its agriculture has 

 more connexion with that of the Grand Duchy than with the rest of 

 Belgium, besides being of very little importance, we do not propose 

 to notice it as a separate province of agricultural Belgium." 



The dependence of the scenery upon the geological structure of 

 these divisions will also be as apparent to our readers, from the fol- 

 lowing quotations, as will the more agricultural and climatal 

 characteristics, which it is the author's object to bring into relief 

 (p. 3-4). 



