On the Physical Geography of the Alps. 369 
clinations are distinguishable ; at their borders a series of greater 
mountains occur, which indicate the line of highest mean eleva- 
tion. Both of these declivities are usually intersected by large 
transverse valleys, parallel to one another aud at right angles to 
the line of the greatest altitude. On both of the other extremi- 
ties also of the “groups” are still smaller transverse valleys. Only 
ina tew of the “groups” does an entirely regular arrangement of 
the valleys occur ; since frequently, sometimes the one, and some- 
times the other system of cross-valleys preponderates. It is worthy 
of remark, that when the longitudinal axes of such “ gronps” 
extend from west to east, their slope to the south is for the most 
part unusually steep, while to the north it is but gradual. ‘This 
_ 18a repetition of the law that we found to obtain generally in the 
Alps; and as the northern plain clearly lies higher than the south- 
ern plain (of the Po), so also the longitudinal valleys in the south 
surround such “ groups” at lower altitudes, than those which sur- 
round them in the north. Other features of the monntain-chains, 
resulting from the transverse valleys, are also described, with ob- 
servations on the mean height of the passes, crests, and summits. 
Mountains and Summits (p. 217).—The mountains of the Alps 
are hot great isolated cones; they rather form portions of definite 
ndges, above the mean gor of which some of the cones emi- 
hently rise. It is only in their neighborhood that we can form a 
correct idea of this condition. Viewed from out of the deep val- 
leys, many of the mountains appear as vast independent pyra- 
mids; while, if we stand over against them on higher ground, 
_ this error is easily corrected, and we perceive that they are only 
portions of a long crest. Only at the extremities of a ridge are 
the mountains seen to stand out independently. 
In the limestone ranges the forms of the mountains are some- 
what different, since here the lower portions very often have steep 
Precipices to an extent that seldom occurs in the crystalline slates. 
At the rear of these precipices are level spaces, above which the 
Summits rise with only gradual ascent. 
the contours of the highest peaks, weathering and erosion 
by hydrometric operations certainly exercise consi erable influ- 
feet (French) above the surrounding parts. The latter are, in all 
probability, connected with the original formation of the moun- 
tain, and not resulting from the disintegrating of the atmosphere ; 
ad the power to remove 
extensive beds of hard rock from around an isolated peak, the 
latter itself ought also to have entirely disappeared long since, as 
lt offers for these operations a proportionally far greater surface 
