170 Reviews — Belt — On the Loes of the Rhine and Danube. 
EEYIEWS. 
I- — On the Loess of the Rhine and Danube. By Thos. Belt, 
F.O.Ö. (Quarterly Journal of Science, Januai-y, 1877.) 
T HE Loess in the valleys of the Rhine and Danube has formed 
the theme of many papers published both here and on the 
Continent, and numerous theories have been advanced respecting 
its origin ; but probably no bolder hypothesis has been put forward 
than that novv propounded by Mr. Belt. 
The paper commences with a description of the character and 
extent of tliis deposit, the position it occupies with respect to the 
rivers and slopes of the valleys being illustrated by woodcuts (in 
which the vertical scale is of course greatly exaggerated). The 
greatest elevation to which it attains in the valley of the Rhine is 
800 feet above the sea-level, whilst in the basin of the Dauube it has 
been found at a height of 1300 feet above the sea. 
Mr. Belt thinks that he has been able to trace the gradual passage 
of the Loess into the northern drift; and the animal-remains that 
are found in it being of the Glacial type (see ante, p. 168), he is led 
to dass the Loess as the Southern equivalent of the northern drift 
(the Upper Boulder-clay of Searles Y. Wood). 
Respecting the origin of this wide-spread alluvium, the author 
shows in the first place that it must have been deposited subsequent 
to the excavation of the valley System, and not during tbe course of 
its formation ; and he complains that “ the usual explanation of the 
facts of the Glacial period is one continued appeal to the hypothesis 
of great oscillations of the eartk’s surfaoe at that time.” “ But is 
tliere,” he asks, “ really no other way of getting water up to the 
heights we require without resorting to this extreme hypothesis?” 
This “other,” and simpler, way is to be found in the theory already 
advanced by Mr. Belt on a former occasion when treating of the 
deposition of the Northern drift, viz. “ That the ice of the Glacial 
period flowed principally down the ocean depressions, and blocked 
up the drainage of the continents as far as it extended, causing 
immense lakes of fresh or brackish water.” Mr. Belt tben explains 
how, according to bis hypothesis, a glacier of fresh-water ice occupied 
the basin of the Atlantic, and reared its snowy crest some 1700ft. 
above the now sea-level, damming back the drainage of Europe, and 
Converting the lowlands into a lake studded with icebergs. This 
huge lake “ was once completely drained ; at first gradually, but 
from about 50Gft. above the present level of the sea suddenly and 
tumultuously by the breaking away of the icy barrier, and thus 
was produced a great deluge or debäcle that swept over the low- 
lands, and covered them with a mantle of false-bedded sands and 
gravel After being thus broken, the icj r barrier soon closed 
up again, and the great lake was refonned, and this time was much 
more permanent.” 
Such is the picture of the Physical Geography of the period given 
us by Mr. Belt; but whether the land to the south is sufliciently 
