126 
WILLIAM SMITH : HIS MAPS AND MEMOIRS 
The volume, whicli consists of 51 quarto pages and two folding 
tables, is di\aded into four sections, viz., "Introduction," "Explanation 
of the Subject of Strata, and of the Colours by which they are represented 
on the Map," " General Account of the Soil and Substrata in the 
Respective Counties," and " Characteristic Distinctions of Soil and 
Surface in the Courses of the respective Strata, described in the Order 
in which their edges successively terminate." 
Ostensibly the volume, as the title indicates, is a companion ta 
the map, respecting which Smith says* : " After twenty-four years of 
intense application to such an abstruse subject as the discovery and 
delineation of the British Strata, the reader may readily conceive the 
great satisfaction I feel in bringing it to its present state of perfection. 
The chances were thought much against my ever completing it on a 
map, of the greater part of our island, large enough to show the general 
course and width of each stratum of the soil and minerals, with a section 
of their proportions, dip, and direction, in the colours most proper to 
make them striking and just representations of nature ; and which 
is the first general mineralogical survey of the island." 
The following extract, taken from pp. 2-3, is probably the first 
published statement in his own words of the great discovery which he 
made in reference to difl^erent strata having typical fossils, in whatever 
district found ; an axiom which forms the foundation of the science 
of geology:— 
" The immense sums of money imprudently expended in 
searching for coal and other minerals, out of the regular course of 
the strata which constantly attend such productions ; and in 
forming canals, where no bulky materials were afterwards found 
to be carried upon them ; prove the necessity of better general 
information on this extensive subject. And I presume to think, 
that the accurate surveys and examinations of the strata, as well 
near the surface of the earth as in its interior, to the greatest 
depths to which art has hitherto penetrated, by the sinking of 
wells, mines, and other excavations, to which I have devoted 
the whole period of my life, have enabled me to prove that there is 
a great degree of regularity in the position and thickness of all 
these strata ; and although considerable dislocations are found in 
In the Introduction. 
