ith regard to what had passed in former periods of time, if the strata
of the globe were in that regular shape which they had originally
assumed in being deposited at the bottom the sea.

The strata, however, are not in that regular shape and position from
whence we might learn, by examining the remaining portions, what had
been carried away from the surface in general; they are found variously
inclined to the horizon; and this we find both occasioned from the
fracture and flexure of those bodies, thus changed from their natural
horizontal state. Thus, though there are in many places immense masses
of strata cut off abruptly, and exposed to view, without the remainder
appearing, we cannot from hence form any estimate of the general
quantity of destruction; at the same time, it must be evident, from a
general inspection, that there has been an immense quantity removed;
and that an immense time had been required in bringing about those
revolutions of things, which are not done by violent changes, but by
slow degrees.

Besides that general conclusion with regard to the destruction of the
strata, there is also in many places a demonstration of that fact, from
a measured minimum of the quantity which had been removed. It is to the
mining business chiefly that we are indebted for that demonstration of
which we now shall give an example.

The coal strata, about Newcastle upon Tyne, dip to the south-east at the
rate of one in twelve, or thereabouts. This is but little removed from
the horizontal position; at the same time, the strata come all up to the
soil or surface in a country which is level, or with little risings. But
in those strata there is a slip, or hitch, which runs from north-east to
south-west, for 17 or 18 miles in a straight line; the surface on each
side of this line is perfectly equal, and nothing distinguishable in
the soil above; but, in sinking mines, the same strata are found at
the distance of 70 fathoms from each other. Here therefore is a
demonstration, that there had been worn away, and removed into the sea,
70 fathoms more from the country on the one side of this line, than from
that on the other. It is far from having given us all the height of
country which has been washed away, but it gives us a minimum of that
quantity.

The examination of what is commonly called a secondary country is not
sufficient to give us an idea of the immense operation of time in
wearing the surface of this earth. It is