DAVIS : THE HARVARD GEOGRAPHICAL MODELS. 
91 
during on-shore storms. The harbor of Genoa is enclosed by an 
artificial breakwater for the protection of shipping. A railroad, 
following this rugged shore, is compelled to tunnel through many 
headlands. No highway runs along the shore east of Genoa; 
westward from that city, it has been only with great difficulty and 
at great expense that the famous Cornici road connecting France 
and Italy has been constructed over or around the headlands. 
The northeastern coast of Spain about Barcelona offers an 
excellent illustration of the same kind. Mountain spurs descend 
to the sea. Villages are generally placed at river mouths between 
the spurs, but harbors are few and poor. Communication with 
the inner valleys is easily led along the larger streams, but move¬ 
ment along the coast is impeded by very hilly roads. Many sugges¬ 
tive comparisons, easily appreciated by young scholars may thus be 
drawn between the ideal model and certain parts of the real world. 
Older scholars may study the model as an example of a frequently 
repeated geological structure and a well-adjusted drainage system. 
Here the employment of a technical terminology is almost essential. 
Good practice may be had in drawing structural sections and in 
sketching surface forms. The mountainous area is easily seen to be 
divisible into two districts of unlike structure ; an area of massive or 
crystalline rocks without manifest foliation on the right, and an area 
of stratified rocks in monoclinal attitude on the left. It is clear that 
the latter rest unconformably on the former, as shown in the 
accompanying section. Several chapters of geological history are 
thus disclosed, all contributing their share to the existing geo¬ 
graphical form. A little exercise of the imagination may picture the 
older rocks long denuded in ancient times, and then submerged to 
receive the unconformable cover of the newer strata. Before 
submergence, the older rocks must have been reduced to a surface 
of moderate relief, a peneplain, KL, as is shown by examining the 
line of contract, L, between the older and younger series. This 
line is comparatively regular; and hence the surface on which the 
overlying strata rest was a comparatively smooth peneplain before 
they were deposited. The lowest members of the stratified series do 
not extend all along the contact line, but occupy only the northern 
part of it; later and later layers overlap upon the contact line 
southward. From this it must be argued that the depression of the 
peneplain was progressive, and that the depression began in the 
north and extended southward. The great thickness of the 
