Principles of Geology. 7 



ous stratum, brown rock, and fossil bed, occur in the very same or- 

 der of succession. It is needless to multiply examples, or every 

 part of the coast from Flamborough to Saltburn might be cited in 

 proof of the above important proposition. And though we only re- 

 fer to a particular district, yet, without doubt, any part of the world, 

 where the strata are distinctly visible, would equally illustrate the 

 doctrine of local constancy in the order of succession among rocks ; 

 because in every country this conclusion has been drawn from actual 

 observations. But it may be inquired : How can the strata be thus 

 traced across provinces and kingdoms? we see them, indeed, ex- 

 posed on the sea-coast, but how are we to guide our inquiries inland, 

 when wells and pits fail us? I answer, that as the different rocks lie 

 not quite horizontal, but gently sloping into the interior, the surface 

 of the earth is formed on their edges. Thus, observe the chalk 

 rising uninterruptedly from Bridlington to Speeton, when — another 

 stratum, the blue clay, having risen from beneath it to the surface — 

 that rock passes off inland, and keeps a regular course through the 

 country. In the same manner, the calcareous grit rises from the sea 

 at Filey, ascends to the summits of Gristhorpe and Red cliffs, after- 

 wards attains the heights of Oliver's mOunt, and ranges away in a 

 direction parallel to the chalk. The same is the case with all the 

 other strata. Thus, the surface of the earth is formed on the edges 

 of the strata, a wise and admirable provision, whereby mankind, 

 though till lately regardless of the benefit, are provided with so great 

 a variety of mineral matter, suited to the various and increasing wants 

 of civilized life. To trace the rocks through the interior of a country, 

 demands, it must be confessed, greater diligence and caution, than 

 when we see them exposed on the sea-side; but the result, thus pru- 

 dently obtained, may be as absolutely trusted. Nor are facilities 

 wanting to the practised inquirer. To him, the forms of hills, the 

 character of surface, the very herbage and color of the soil, afford 

 most valuable data, and when corrected by the accounts of wells and 

 pits, and observations of roads and water-courses, leave little room 

 to doubt the accuracy of his deductions. 



This being proved, we may now inquire if there be a conformity 

 of rocks over large districts, an accordance of composition, a simi- 

 larity of succession, and a connexion of strata, sufficient to unite to- 

 gether observations in distant countries : without doubt thei-e is such 

 conformity. The series of strata in Yorkshire, taken in a general 

 way, is the following : chalk, gault?, Kimmeridge clay, coralline 



