Report on the Agriculture of Belgium. 
5 
continuation of the " inclined plane " of Northern Belgium, and 
rise to a height of nearly 600 feet on the verge of the Meuse valley. 
The climate varies more than that of Flanders, the mean 
summer temperature being as high as 65° Fahr., and the mean 
winter temperature as low as 35 Fahr. The rainfall is less in 
amount and is spread over a smaller number of days, but snow 
usually falls on from twenty to twenty-five days in the year. 
These peculiarities, added to the additional strength of the land, 
have doubtless caused those differences in agricultural practice 
which we shall have to notice. 
3. The Polders and River-valleys. — The soil of this divisioa 
(ruled blue on the map) consists of what is usually termed 
alluvium, namely, an argillaceous soil, containing a varying pro- 
portion of sand and a little lime. Generally, it is extremely 
fertile, especially when first reclaimed. The term " Polders " is 
properly applied to alluvial flats reclaimed from the sea or the 
mouths of rivers, and protected by dykes against high tides, floods, 
and storms. The whole of the Dutch and Belgian coast-line consists 
of this description of land, and a large portion of the kingdom 
of Holland comes under the same title. With this land we have 
classed the alluvium of the river-valleys, which has been formed 
by the deposition of mud by the rivers, especially during floods, 
in those portions of their course where the velocity of the 
stream is not sufficient to transport the mud brought down from 
the higher country.* This alluvium differs very slightly from 
the Polders in actual composition, but very materially in agri- 
cultural use ; for the former, especially when irrigated, forms 
extremely rich feeding and meadow land, while the latter is 
almost exclusively devoted to the growth of corn. In climate, 
the Polder-region resembles the adjoining portion of Flanders, 
differing only to such an extent as may be caused by the in- 
fluence of the soil on temperature and humidity. Physically, the 
Polders form a nearly plane surface, the undulations being scarcely 
visible, and rarely attaining a greater height than 4 or 5 feet. 
4. The Plateau-region of Southern Belgium. — A glance at our 
map will show that south of the Meuse the surface rapidly rises 
to a height of nearly 800 feet, between which elevation and the 
line of 1000 feet it forms a somewhat triangular plateau. Still 
further south the same phenomena are repeated ; the surface 
rises even more rapidly than before from the 1000 feet line to a 
mean height of about 1500 feet, and then a plateau of more 
broken character is reached. The former of these mountain- 
plains is known as the Condroz, and the latter as the Ardennes. 
* Owing to the small scale of the map we have not been able to show these 
river-deposits, except where they have a great breadth, but in reality they border 
most of the streams in Northern and Central Belgium. ^ 
