PFT, (4i5.2..] “I'L £D.Ssr Agass . : 
vs, , The interior valleys, and b, the nae of the chain, where some 
of them are found, 
n, The lake of Neuchatel. “ ‘ 
. 8, The lake of Geneva. 
The difference of altitude between the Alps and gros distrbutted 
over a space of fifty miles, gives an inclination of no. more than two 
degrees. Now, no current could force, or rather float, masses of ston e, 
weighing 1,000 tons, across an uneven valley of such breadth, although 
the difference of level were-much greater. Even if the valley had 
then been filled up with gravel, or other solid materials, and formed a 
regular inclined plane, as Ebel and Dolomieu assumed, the blocks could 
not have been moved over it by water; or, if moved, they would have 
been rounded by attrition; and, instead of being disposed in zones, 
they would have been accumulated pel mel at the bottom of Jura. It 
must be kept in mind, that the erratic blocks are found on the Italian 
side of the Alps as well as the Swiss, and that currents and inclined 
planes would be required in both directions. 
A more recent hypothesis, which assumes that the boulders were 
transported by icebergs when the great Swiss valley was under the sea, 
is much more plausible. Agassiz objects to it, that it does not account 
for the coat of sand and gravel covering the sides of the mountain on 
which the large blocks generally rest, nor for the striated, grooved, and 
polished surfaces, nor (he might have added) for the Japiaz and creuz, 
and the lateral moraines which deviate from a horizontal position. 
It will be anticipated that Agassiz transports the boulders across the 
great valley on a bridge of ice. He observes that the eastern Alps, as 
they haye disturbed the dilwvium containing bones of elephants, must 
have been raised up since that deposit was formed, and their upheaval 
is the last cataclysm, or geological convulsion, which has visited Europe. 
Previous to this event, an immense mass of ice had covered the surface 
of the northern parts of the old and new world; “but when the up- 
heaval of the Alps took place, this formation of ice was raised up like 
the other rocks; that the fragments detached from the fissures of up- 
heaval ( fentes du soulevement) fell upon its surface, and without being 
rounded—since they were not exposed to friction—moved along the in- 
| * elined surface of the sheet of ice, in the same manner as the fragments 
| of rock which fall upon glaciers are carried to their sides in conse- 
quence of the continual movement produced in the ice by its alternate 
thawing and cone ans at me different hours of the day, and the dif 
ferent season 
“ After = naieannl of the Alps, the earth must have recovered a 
higher temperature; the ice in melting produced large funnels (enton- 
noirs) at the places where it was thinnest ; wiles of erosion were ex- 
Vol. xin, No. 2.—Jan.—March, 1842. 
