1038 ON THE LIGNITES AND CLAYS OE BOVET TEACET, DEVONSHIRE. 
Explanation op the Plates. 
PLATE LII. 
Is copied, with very slight alterations, from the twenty-sixth sheet of the Map 
published by the Geological Survey of Great Britain ; and, like the original, is on the 
scale of 1 inch to a mile. 
PLATE LIII. 
Is a section of the Bovey formation, in the plane of the Dip of the beds. It is drawn, 
from the measurements obtained in the “ first section,” given in the text (see p. 1022, &c.), 
on the scale of or 1 inch to 14 feet. The Dipt amounts to 12^°, and is in the direction 
S. 35° W. magnetic. The beds in which fossils were found are those the numbers of 
which are placed opposite them in the margins. 
PLATE LIV. 
Contams two sections of the formation, in the plane of the Strike of the beds, and is 
intended to show the nature of the evidence for the existence of the “ Fault'" The scale 
of thickness, in each, is y|-q, or 1 inch to 10 feet ; and the total depth below the surface 
is 99 feet. 
The symbols have the same meaning in both. 
a is the “ old engine-shaft.” 
h. The eastern end of the “ Coal-pit 56 fathoms west of a. 
c. Mr. Divett’s “boring;” 70 fathoms east of a. 
d, 80 feet below the surface, is a horizontal excavation veiy near the engine-shaft, 
and opening eastward out of a “ working” which runs parallel and adjacent 
to the “ Fault ” (see fig. 2). 
ef is the hypothetical of the “ Fault.” 
With the omission of a few unimportant local difierences, the western section repre- 
sents the ascertained succession and thickness of the beds from a to nearly half a mile 
westward. They are probably continued much further in this direction, but are known 
to terminate eastward abruptly at the “Fault,” ef, immediately east of a. The lowest 
bed shown is the 62nd in the “ pit ” sections. 
The eastern section is drawn from the data obtained in Mr. Divett’s “boring” at c, 
(p. 1033,) and shows all the beds cut there. These are assumed to extend, in the same 
order, westward to e f; and though no excavations have been made at the surface in 
the intermediate space, the assumption is by no means gratuitous, since a bed of sand, 
having the same characters and at the same depth below the sm’face, has been met with 
both in the “ boring ” c and the excavation d. 
Though the existence and situation of the “ Fault ” has been well ascertained, the 
angle which its plane (1), e f makes with the horizon is not so well known. In the 
absence of complete evidence on this point, it has been thought best to draw it at right 
angles, more especially as the evidence, so far as it goes, is to that effect. 
