WILLIAM SMITH ; HIS MAPS AND MEMOIRS 
97 
identity of character, continuity and uniform thickness in length and 
breadth for many miles, the great incHnation of the beds in mountainous 
counti'ies, and their approach to the horizontal position in flat ones ; 
but he clearly explains the arrangement of the strata in England. He 
states : " Let a number of leaves of paper, of several different sorts or 
colours, be pasted upon one another ; then bending them up together 
into a ridge in the middle, conceive them to be reduced again to a 
level surface, by a plane so passing through them as to cut off all the 
part that has been raised ; let tbe middle now be again raised a little, 
and this will be a good general representation of most, if not all large 
tracts of mountainous countries, together with the parts adjacent, 
throughout the whole world. From this formation of the earth it 
will follow that ive ought to meet with the saute kinds of earths, stones and 
minerals, appearing at the surface, in long nm roiv slips, and lying parallel 
to the greatest rise of any long ridge of mountains ; and so in fact we find 
them In Great Britain we have another instance to the same 
purpose, where the direction of the ridge varies about a point from 
N. by E. to S. by AV. of which I could give many undoubted proofs. . 
As an example of the large extent of strata in level areas he says : " the 
chalky and flinty countries of England and France, which (excepting 
the interruption oi the Channel and the clays, sands, etc., of a few 
counties), compose a tract of about 300 miles each way," and he adds 
that the highest rise of the ridge, and the inclination of the strata, 
have very considerable irregularities," and this often makes it difficult 
to trace the appearances I have been relating, which, ivithout a general 
knowledge of the fossil bodies of a large tract of country, it is hardly 
possible to do." 
JOHN WHITEHURST, 1778. 
In 1778* AVhitehurst pubhshed an Inquiry into the Original 
State and Formation of the Earth," which contained information on 
'•'organised fossils," and he includes a chapter on "The Structure 
of Derbyshire and other parts of England." He states : " The arrange- 
ment of the strata being such that they invariably follow each other 
as it were in alphabetical order, or as a series of numbers. / do not 
wean to insinuate that the strata are alike in all the different regions of 
the earth with respect to thickness or quality, for experience shows the 
* 2nd ed., 1786. 
