624 DIVERSION OF THE RHINE. 
rent, of water from the Atlantic through the Straits of Gibral- 
tar; the proportion of salt it contains would be increased, and 
the animal life of at least its southern borders would be conse- 
quently modified ; the current which winds along its southern, 
eastern, and north-eastern shores would be diminished in force 
and volume, if not destroyed altogether, and its basin and its 
harbors would be shoaled by no new deposits from the high- 
lands of inner Africa. 
In the much smaller Red Sea, more immediately perceptible, 
if not greater, effects, would be produced. The deposits of 
slime would reduce its depth, and perhaps, in the course of 
ages, divide it into an inland and an open sea, the former of 
which, receiving no supply from rivers, would, as in the case of 
the northern part of the Gulf of California, soon be dried up 
by evaporation, and its whole area added to the Africo-Arabian 
desert ; the waters of the latter would be more or less fresh- 
ened, and their immensely rich marine fauna and flora changed 
in character and proportion, and, near the mouth of the river, 
perhaps even destroyed altogether; its navigable channels 
would be altered in position and often quite obstructed ; the 
flow of its tides would be modified by the new geographical con- 
ditions; the sediment of the river would form new coast-lines 
and lowlands, which would be covered with vegetation, and pro- 
bably thereby produce sensible climatic changes. 
Diversion of the Rhine. 
The interference of physical improvements with vested 
rights and ancient arrangements, is a more formidable obstacle 
in old countries than in new, to enterprises involving anything 
approaching to a geographical revolution. Hence such pro- 
jects meet with stronger opposition in Europe than in America, 
and the number of probable changes in the face of nature in 
the former continent is proportionally less. I have noticed 
some important hydraulic improvements as already executed or 
in progress in Europe, and I may refer to some others as con- 
