102 
WILLIAM SMITH I HIS MAPS AND MEMOIRS 
<?xpresses the order of the strata, by colours. The maps referred to 
by the late M. Desmai-est, as annexed to the Encyclopedie Methodique, 
have not yet a,ppeared. But that author insists upon the great in- 
struction to be derived from combining vertical sections with hori- 
zontal maps, and the benefit arising in general from even the attempt 
to reduce to maps, the results of geological investigation." 
JAMES PARKINSON, 1811. 
In the first volume of the quarto Transactions of the Geological 
^Society of London, 1811, p. '>25, is a paper on Observations on some 
of the Strata in the Neighbourhood of London," by James Parkinson. 
He states that the method of identifying fossils with particular strata 
was '' long since recommended by W. Smith, who first noticed that 
certain fossils are peculiar to and are only found lodged in, particular 
strata ; and who first ascertained the constancy in the order of super- 
position, and the continuity of strata of this island.'' He adds 
that "these observations have also lately occurred to Messrs. Cuvier 
and Brongniart whilst examining into the nature of the strata in the 
neighbourhood of Paris." The following is a translation of Parkinson's 
quotation : — 
" This constancy in the order of superposition of the thinnest of 
layers and along an extent of 12 myriametres (75 miles) is, in our 
opinion, one of the most remaikable facts that we have established 
in the course of our researches. From them, for the arts and for 
geology, should result consequencCvS the more interesting the more 
certain they are. 
^' The method that we have adopted for recognising in the middle 
of such a large number of calcareous beds, a bed already observed in 
a place a long distance away, is taken from the nature of the fossils 
discovered in each stratum ; these fossils ai-e always in a general way 
the same in corresponding strata, and present differences of species 
sufticiently distinguishable from one system of strata to another 
system. It is a method of examination which has' not up to the j^resent 
deceived us." 
