2 EXPLANATION OF PLATE 1. 
and to one another, more intelligibly than I have ever seen 
expressed elsewhere. This original drawing by Mr. Web- 
ster 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. Web- 
ster 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 princi- 
pal 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 Pheno- 
mena 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. 
