and to one another, more intelligibly than I have ever seen
expressed elsewhere. This original drawing by Mr. Webster
has formed the basis of the present enlarged and
improved section, into which many important additions
have been introduced by the joint suggestions of Mr. Webster
and myself. The selection and arrangement of the
animals and plants is my own; they have been drawn and
engraved (together with a large proportion of the wood-
cuts) by Mr. J. Fisher, of St. Clements, Oxford,
For facility of reference, I have numbered the principal
groups of stratified'rocks represented in the section,
according to their most usual order of succession; and
I have designated by letters the crystalline or unstratified
rocks, and the injected masses and dykes, as well as the;
metallic veins, and lines of fracture, producing dislocations
or faults. The crowded condition in which all the Phenomena
represented in this section, are set together, does
not admit of the use of accurate relative proportions,
between the stratified rocks and the intruded masses, veins,
and dykes by which they are intersected. The adoption
of false proportions is, however, unavoidable in these cases,
because the veins and dykes would be invisible, unless
expressed on a highly exaggerated scale. The scale of
height throughout the whole section is also infinitely greater
than that of breadth. The plants and animals also are
figured on no uniform scale.
The extent of the different formations represented in this
section, taking their average width as they occur in Europe,
would occupy a breadth of five or six hundred miles. A
scale of heights, at all approaching to this scale of breadth,
would render the whole almost invisible. The same cause
makes it also impossible to express correctly the effect of
vallies of denudation, which are often excavated through
strata of one formation into those of another subjacent
formation.
As it would encumber the section to express Diluvium,
wherever it is present, it is introduced in one place only,
which shews its age to be more recent than the newest of
the Tertiary strata; it is found also lodged indiscriminately
upon the surface of rocks of every formation.
Granite.
In our early Chapters we have considered the Theory
which refers unstratified rocks to an igneous Origin, to be
that which is most consistent with all the known Phenomena
of Geology, and the facts represented in the Section
now before us are more consistent with the Postulates of
this Hypothesis, than with those of any other that has
hitherto been proposed. I have, therefore, felt it indispensable
to adopt its language, as affording the only terms by
which the facts under consideration can be adequately described.
Assuming that Fire and Water have been the two
great Agents employed in reducing the surface of the globe
to its actual condition, we see, in repeated operations of
these agents, causes adequate to the production of those
irregular Elevations and Depressions of the fundamental
Rocks of the Granitic series, which are delineated in the
lower Region of our Section, as forming the basis of the
entire Superstructure of stratified Rocks.
Near the right extremity of this Section, the undulating
surface of the fundamental Granite (a. 5. at 6. a. 7. a. 8.)
is represented as being, for the most part, beneath the level
of the Sea.
On the left extremity of the Section (a. 1. a. 2. a. 3.) the
Granite is elevated into one of those lofty Alpine ridges,
which have affected, by their upward movement, the entire
series of stratified Rocks.
Corresponding formations of Primary and Transition