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its origin or incrcafe but to the quantities of earthy matter continually brought down and
depofitcd by this river, which, to all appearances, were formerly infinitely more confiderabie
than at prefent. 2. That the fea once covered this fertile plain; and that the greatefl: part
of Lombardy may be confidered as an encroachment made on that element by a quantity of
fragments detached from the primordial and fecondary chain of mountains, which were at
firil hurled by the fea in its lail retreat, and then carried along by the waters of tlic Po,
which in fome degree ftill continues to depofit tliem, as before mentioned, by means of the
frequent inundadons caufed by the overflowings of the P6 in the confines of Feri'ara and
Bologna, which are increafed by the eagerncfs of the inliabitants of thofe provinces, who
imfortunately attempted to reftrain the waters of that formidable river too foon by banks,
dykes, &c.
II. From the direfUon of tlie valley of Lombardy, and of all the fecondary ones which
terminate in it; from the extreme difference in the ele\'ation of the head of thefe fecondary
valleys fituated at the foot of the Alps, and likewife firom their number, compared to thofe
on tlie weft and fouth-weft of the fame mountains; from their irregular form, number,
and great degree of abruptuefs, which exift likewife in the fecondary and tertiary mountains
on the eaftem fide of the granitic peaks, in comparifon to thofe of the fame order on tlie
weilem: in Ihort, from the calcareous chain of hills which furround all Lombardy; I
think I may venture to conclude: 1. That the motion of the fea, in its firil mutation or
change, had a dire£Bon tending nearly from weft to eaft. 2. That at firft it rofe to a great
height, which appears to be fully proved by the calcareous matter, containing maritime
ihells, now found lying on fome of the primitive rocks of the Alps. 3. That its motion
and retreat, or fubfiding, were at firft extremely rapid. 4. That the fea having rofe above
the plains which form the high valleys of the Alps, it afterwards precipitated itfelf towards
the eaft, and dug by its weight and velocity the valleys which are at their feet, mutilating
and chamfretting the fecondary mountains which intercepted its paiTage. 5. That the fea,
having in procefs of time abated in its motion, had by its fediment formed the fchiftus and
fecondary mountains, which defcribe a kind of zone to the plain of Lombardy: in Ihort,
6. That it is evident, that the fea remained or ftopped a much longer lime on the weftera
iide than on the eaftem.
III. From the enormous malTes of granite and primitive rock which now lie ifolated on
the fummit of feveral high calcareous, fchiftous, and fandy-hills in Piedmont, to which
they have not the leaft analogy, I am naturally led to believe, l. That the foil of the upper
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part of the valley of Lombardy was, when ftill covered or fubmerged by the fea, nearly
as elevated as the fummit of thofe hills are at prefent. 2. Tliat thefe granitic maffes
were moil probably driven on the top of thofe hills by the accelerated a<ftion of the fea, as
I have previoufly obferved in a former part of my work, and left in that ifolated flate by
the fame current, which, by gradually furrowing the foil in various direilions, formed an
innumerable quantity of fmall irregular valleys, which have, however, in general, their falient
or prominent angles uniformly oppofed to the concave ones.
IV. From tlie extreme degree of cold particularly experienced on the Cols dc Tende,
Fineftrc, and Argentera, &c. though lefs elevated than Mont Cenis, I draw the following
conclulions. l. That die height or degree of elevation of the mountains above the level of
the fea, have lefs influence than tliat which they have above their valleys, in order to the
abfolute determination of the kind of climate which exifts on their fummit; provided, however,
their height does not exceed one thoufand or twelve hundred toifes, that being nearly
the zone in which the fnow is permanent.
V. From the irregular inclinations or direilions fo generally found in the beds or flrata
of tlie fecondary mountains, and ft-om their abruptnefs, breaks, and quantity of heterogeneous
matter fo frequendy contained in their cavities, I am of opinion, l. That thofe
mountains could not have given way and funk, except at the time wlien their fummits
were entirely fubmerged by the fea: indeed this fuppofition appears to be fully elucidated
by the calcareous matter containing marine foffils, which generally fill the vacuum formed
by the different breaks of thofe mountains, and which is likewife fometimcs found on their
fummits. 2. That they could not have thus broken or feparatcd, but from the efFeft of
fubterraneous caverns formed in the interior of the globe, the vaults of which, from being
progrefiively over-charged by a continual accumulation of calcareous particles depoiited by
the fea, have fimk or given way, as Chap. V. fig. i and 2, will, I flatter myfelf, clearly
demonftrate.
VI. From the number of mountains formed of grcs, or fand-ftone, mame, or marl, and
pudding-ftone, which lie on others of different fpecics, fuch as gi-anitc, rock-ftone, &c,
which likewife vary as to the reciprocal inclinadons of their flrata; alfo, from the irregularity
and extreme verticality in tlie flrata of the mountams of fdiift, which even form a
right angle with the horizon; in fine, from the general diforder or confufion which appear
fo confpicuous in the fecondary and tertiary mountains fituated towards tlie weft and
fouth-weft chain of the Alps, I am led to believe: l. That the wonderful changes which
in
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