of the world, the land is perishing continually; and
this is that which now we want to understand.

Upon the one extremity of our land, there is no increase, or there is no
accession of any mineral substance. That place is the mountain-top, on
which nothing is observed but continual decay. The fragments of the
mountain are removed in a gradual succession from the highest station to
the lowest. Being arrived at the shore, and having entered the dominion
of the waves, in which they find perpetual agitation, these hard
fragments, which had eluded the resolving powers natural to the surface
of the earth, are incapable of resisting the powers here employed for
the destruction of the land. By the attrition of one hard body upon
another, the moving stones and rocky shore, are mutually impaired. And
that solid mass, which of itself had potential liability against the
violence of the waves, affords the instruments of its own destruction,
and thus gives occasion to its actual instability.

In order to understand the system of the heavens, it is necessary to
connect together periods of measured time, and the distinguished places
of revolving bodies. It is thus that system may be observed, or wisdom,
in the proper adapting of powers to an intention. In like manner, we
cannot understand the system of the globe, without seeing that progress
of things which is brought about in time, thus measuring the natural
operations of the earth with those of the heavens. This is properly the
business of the present undertaking.

Our object is to know the time which had elapsed since the foundation of
the present continent had been laid at the bottom of the ocean, to the
present moment in which we speculate on these operations. The space is
long; the data for the calculations are, perhaps, deficient: No matter;
so far as we know our error, or the deficiency in our operation, we
proceed in science, and shall conclude in reason. It is not given to man
to know what things are truly in themselves, but only what those things
are in his thought. We seek not to know the precise measure of any
thing; we only understand the limits of a thing, in knowing what it is
not, either on the one side or the other.

We are investigating the age of the present earth, from the beginning of
that body which was in the bottom of the sea, to the perfection of its
nature, which we consider as in the moment of our existence; and we have
necessarily another aera, which is