374 Mr. Which on the [May, 



evidently derived from the shale and sandstone on which it 

 rests. The question to be resolved is, " Why the current of 

 diluvian waters, possessing sufficient impetus to bring enormous 

 fragments of rocks from great distances, did not denudate the 

 strata of the light soil in which these masses are now embedded 

 not only in the lower but in the vpper pari of the earth resting 

 upon the more solid substrata." I remain, Sir, 



Your most obedient servant, 



N.J. Winch. 



Article VIII. 



On the Geology of the Eastern Part of Yorkshire, 

 By N. J. Winch, Esq. FLS. and MGS. 



(To the Editor of the Annals of Philosophy.) 



SIR, T^evccastlc-upon-Tyne^ March 20, 1822. 



The Rev. G. Young, and Mr. Bird, of Whitby, have just 

 published a quarto volume on the Geology of the Eastern Part 

 of Yorkshire, which, through the favour of a subscriber to the 

 book, I have had an opportunity of perusing. Of the merit or 

 demerit of the work, I do not feel myself inclined to speak, but 

 as the authors have travelled out of their road for the purpose of 

 writing strictures on two essays of mine printed in the Transac- 

 tions of the Geological Society of London, I shall take leave to 

 rebut the charges of inaccuracy and presumption brought against 

 me by these gentlemen. 



The first is comprised in the following note, p. 170 : 'f Mr. W. 

 is mistaken in asserting (vol. iv. p. 7, Geological Transactions), 

 that the white oolite limestone at Hartlepool contains no shells 

 or marine exuviee; the authors found in it both univalves and 

 bivalves, especially the latter." Now every geologist knows, 

 that one part of a stratum may contain, and another be devoid, 

 of organic remains ; and that there were none in the quarry at 

 Hartlepool, when I inspected it, I am certain, for specimens of 

 the rock taken at the time are still in my possession. The next 

 is in the letter press at p. 171, under the head of Dykes : *Mn a 

 quarry at Whitley, near Cullercoats, where there is an extensive 

 mass of magnesian limestone, detached from the great beds of 

 the county of Durham, there is a similar dyke (see Geol. Trans, 

 vol. iv. p. 25), which intersects the coal and sandstone strata 

 under the limestone, and does not pass through the latter, &c.' 

 In reply to this, allow me to observe, I never said the dyke at 

 Whitley was a basaltic dyke. My words at p. 25, are : ^' Besides 

 the fissures filled with basalt, others of a very different nature 

 intersect the coal field. These, if large, are called dykes, but 



I 



