192 Mr. Faretfs Account of the Rivers 



above mentioned, I was favoured by its indePntigahIc Ait- 

 thor, with communications, respecting the numerous 

 Collieries in or near Derbyshire, which are pnuiud m my 

 3Ath volume, page 431; the various Alines ot Lead, 

 Zinc, Copper, }kc. which are given in vol. xxxvii. page 

 106, and respecting the nuu)erous Ililli and the upper 

 stratum of each, which will be found at page \G\ of the 

 same volume. On comparing the papers and lists above 

 referred to, with the corresponding parts of the volume 

 now before me, 1 find them so far from mere copies, 

 that they seem essential auxiliaries of each other, as every 

 new and different arrangement of a large scries of facts 

 and phoenomena must prove, to the anxious inquirers 

 after Geological or other truths. It is my intention, ifi 

 ail early number, to give a copy of the Map (f Ridges 

 and Hills, which has been mentioned and- referred to, 

 vol. xxxvii. p. ICi; and wherein the total lengths and 

 widths or extents and shapes, of the excavations between 

 the several Ridses that separate the Hiver-Districts of 

 Derbyshire, will appear, and 1 have selected the account 

 of the beds of these Rivers, &c. for insertion herein (as 

 the first of some extracts which I mean to give occa- 

 sionally from Mr. Farcy's volume), as following up what 

 is already begun in my Magazine, by the account of 

 these Ridges and the Hills on them, and throwing some 

 additional liglit on that very fundamental point of Geo- 

 loo^ical Theory, the manner and circunjstances of the 

 excavation or formation of Falleys on the surface of the 

 Earth, which it will be recollected, engaged the pens of 

 two of iny Correspondents in the 33d an > ^4th volumes j 

 and I will take the present opportunity of saying, that 

 observations of facts and discussions (temperately con- 

 ducted) on Geological S7ibjects, shall always receive atten- 

 tion, and as early insertion as possible in the Philoso- 

 phical Magazine ; and not less so, than if regard to uni- 

 formitv in the sets of my voluines would have allowed 

 me, to make a more express alteration in its Title than I 

 have done, by calling it in future the Philosophical and 

 Geological Magazine, as several of my ingenious Cor- 

 respoTidents have wished.— Editor.] 



1 . Streams and Rivers. 



In speakin'Z of the Surface of Derbyshire, in the 1st Sec- 

 tion of this "Chapter, and describing the 41 Ridges of high 

 Land, page 4, which are shown in the Map fafciag page 1, 



the 



