tion of the surface was thus covered. . Only the very summits 
of the highest ranges had glaciers upon them, and the amount of 
snow and ice thus stored away would seem to have been far too 
small to produce by their melting a general filling of all the 
valleys with water unless we assume — which is certainly not 
probable — that the change was almost instantaneous. 
It is certain that both in Asia and North America the phenom- 
ena of desiccation are on too grand a scale by far to be supposed 
to have anything to do with cutting down of forests. The dry- 
ing up has been commenced before man interfered with nature, 
and has been continued without reference to his puny operations. 
If, as has been suggested, the records of rain-gauge and ther- 
mometer are too incomplete and unsatisfactory to throw any light 
on the question of climatic changes of importance in modern times, 
the question arises whether there are not other sources of in- 
formation to which recourse can be had. For instance, records 
have, in parts of Europe, been kept for many years of the flow 
of water in some of the principal rivers. Can any results be 
obtained from a comparison of these records with a view to the 
settlement of the question, whether the amount of water passing 
from year to year at certain points has diminished, increased, or 
remained constant? The eminent geographer, Berghaus, was 
one of the first to take up this investigation. He worked up the 
observations of the Rhine made at Emmerich, those of the Elbe 
at Magdeburg, and those of the Oder at Kiistrin, and came to 
the conclusion that each of these rivers had decreased in volume 
during the past hundred years, and that there was reason to fear 
that they would eventually have to disappear from the list of the 
navigable streams of Germany. Later than this, an eminent 
hydraulic engineer, Gustav Wex, chief director of the important 
“ Donauregulirung,”! and a high government official, undertook 
the same investigation, but with much more detail. His p : 
however, are similar in character to those of Berghaus, and a e 
ncipal 
to demonstrate beyond the possibility of doubt that the pri 
streams of Middle Europe, namely, the Danube, the Rhine, thè 
Elbe, the Vistula, and the Oder, together draining an area © 
570,000 square miles, have for many years been carry! 
stantly diminishing quantity of water. The longest seri 
servations used in coming to this conclusion is that of 
at Magdeburg, where the records go back for one hund 
1 A great work undertaken with a view to the regulation and improvement of e 
channel of the Danube at and near Vienna. i 
518 Are We Drying Upi [September 
E at ORE a TE T E, ASe E A 
ing AAE 
es of | oe | 
the Elbe 
red and 
vat ee eth ofl tte ean Do ee eee etre an ein a 
