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Marseilles in order to repeat the observations heretofore made on the same spot by
Pythias, found that the inclination was decreased to 23® 28' 24" : in fine, Messrs. de
Lalande and la Grange, well known for their knowledge in astronomy and mathematics,
have, in consequence of several interesting and curious observations, found,
within a few years, the inclination of the ecliptic to the equator to be only 23= 28'0":
whence those gentlemen have concluded, that there doubtless exists a gradual tendency
to co-incidence between the two polar circles \ and the diminution of the angle
the latter has calculated at about tliirty-six seconds in a century. Seventhly, that, as
it is a fact well known that the northern part of our globe has a great deal less sea than
the southern, and that most of the continents in the latter, which also comprehend more
islands and volcanoes, terminate in a point, it may be reasonably presumed that the last
retreat of the waters of the sea has, in a great measure, been performed on that side, or
nearly from north to south, and that to the great or violent currents only (which at that
epoch probably took place) may be attributed the sharp-edged or pointed appearance of
the extremity of those continents. Eighthly, that, as the highest mountains of our globe
are likewise all comprised between the forty-fifth degree of latitude on each side of the
equator, and as the major part of those mountains are now acknowledged to owe their
origin to the effects of crystallisation, the sea must then consequently have made a
longer stay on that part of the globe, and covered it to a more considerable height
than towards the poles, since that crystallisation could not possibly be effected without
being in a fluid state; and that the major part of those mountains exceed eight thousand
nine hundred yards above the level of the sea, whereas there are none found of equal
height from the forty-fifth degree to the poles. Ninthly, that the rocks we denominate
secondary are stated to be of posterior date to those of granite and porphyry, as they are
often found lying on the latter; and those termed tertiary are deemed of still more
modern date, since they are generally discovered resting on the two former, often containing
different kinds of fossils, and impressions of bodies belonging to the animal and
vegetable kingdoms; in fine, that the greatest part of sand-stones doubtless owe their
origin or formation to the various submersions experienced by our continents. Tenthly,
that these different submersions and emersions must have evidently produced a number
of volcanoes and subterraneous fires, by the successive deposit of the mineral
and pyritous matter contained in the water, part in crystallisation, and part in dissolution,
which, having afterwards become heated by the contact of the water, as by the
effect of violent fermentation, during the different retreats of the sea, niay be supposed
to have formed a number of subterraneous caverns, into which a part of the water
insensibly filtered, and which, in process of time, being converted into steam or vapour,
raised up most of the strata belonging to the tertiary mountains, which then served as
vaulted roofs to those caverns; for the force of expansion continually increasing by the
effect of the subterraneous fires, and the resistance which opposed remaining nearly the
same, these vaults naturally burst forth, soon after, with an excessive crash or explosion,
in like manner as a vase well shut (were it even of metal), in which water had been
converted to vapour by the efi^ect of fire,—it being now known that the strength of water,
reduced to vapour, is to that of gunpowder as U.,000 to 500. Eleventhly, that there certainly
does not remain a doubt of the actual existence of volcsnoes, or subterraneous
fires, under the bottom of the ocean, in various parts of the world, there having been
many instances of mountains rising out of the sea; as Monte Nuovo, near Naples,
which acquired its present elevation in forty-eight hours; besides others in South-
America, the Archipelago, &c. where there exist a number of volcanoes, some of
which are in full activity, and many that have been extinct from time immemorial.
Twelfthly, that it is highly probable that those volcanoes may have been, at different
periods of time, submerged by the sea,—since there exist, in several parts of Europe, as
Auvergnc, Vivares, Brisgaw, and along the Rhine, many of them, the lavas and craters
of which are, even at present, almost covered by calcareous and argillaceous strata,
containing various species of marine fossils. And again, lastly, that, besides the force
of expansion and volcanic operations, the two great agents, which I consider as the
original or primitive causes, which have produced the greatest part of our extensive
valleys and lakes, I admit as probable, and perfectly consistent with the theory which
I have advanced, that several lesser valleys, which may literally be termed galleries
only to the former, likewise owe Uieir formation to a sudden sinking or falling-in
of their vaulted roofs, occasioned by the successive sediments left by the sea at the time
of its different retreats; which sediments or weight, becoming superior to the resistance,
ended by crushing them entirely.
Hence I am led to conceive, that from the above causes have resulted that confusion
and irregularity which at present exist in the major part of the last-mentioned valleys:
though to these might likewise be added the electric fluid, the effects of which must,
at that period, have been very considerable, and no doubt have greatly contributed