Lankester— Crag. 
105 
ancient city of Antwerp, which, always an interesting spot to the 
tourist, has at the present time an addi- 
tional interest to such as are students 
of geological phenomena. Immense 
fortifications are being placed round 
the outskirts of the city, forming a 
semicircle some five or six miles in 
extent; and the deep trenches have 
displayed a series of sandy and argilla- 
ceous deposits, abounding in fossils, 
and presenting a strong resemblance 
to the Crags of Suffolk. How the for- 
tifications of Antwerp are to be garri- 
soned, or what their ultimate utility 
may be with the small handful of sol- 
diers which Belgium can supply, unless 
aided by this country, we need not 
stop to inquire. Let us plunge at once 
into the trenches, and examine the sec- 
tion,—a proceeding, by-the-by, strictly 
forbidden by the Government, and but 
to be accomplished by the payment of 
a frane to the sergeant on duty. The 
writer was enabled in this manner, last 
summer, to examine the strata in a 
satisfactory manner, and to form a good 
collection of their organic contents. 
As in Suffolk, the Crag-deposits rest on 
an Hocene clay, and are capped by 
Pleistocene strata, of an age equivalent 
probably to that of the Loess of the 
Rhine. ‘The accompanying diagram 
will show the arrangement of the vari- 
ous beds. The section is taken from 
the River Escaut to the Canal de la 
Campine, a distance of about 19,000 
yards; the trenches in front of the 
eight detached forts, surrounding the 
line of works, furnishing the data upon 
which itis constructed. An admirable 
little paper (presented to the Royal 
Academy of Brussels) by M. Ad. De- 
jardin, Captain of Engineers, gives a 
description of two sections; one pass- 
ing by the detached forts, and another 
along the semicircular line of entrench- 
ment. The annexed diagram is con- 
structed from my own observations, 
assisted by the excellent drawing of 
the Belgian Engineer. In many places 
Canal 
Fort 
(About 19,000 yards in length.) 
Section along the Trench from the River Escaut to the Canal de la Campine. 
=| Pleistocene. 
= Lower or Black Crag. 
FSS] Middle Crag. 
===] Eocene Clay (Systéme Rupélien). 
(See foot-note, p. 106.) 
Unfossiliferous Green Sand. 
The bottom of the Trench is uneven, as represented in the section. 
