1824.] Dr. Fitton on the Strata below the Chad:, &jc. 365 



made a voyage to the Baltic at the public expense, I have to 

 state, that with regard to the former, no report whatever has been 

 received at this office from any one vessel supplied with protectors, 

 nor am I aware that any one of them has returned into port. And 

 with regard to the second point, I can safely say, that Sir Hum- 

 phry's passage to the Raze of Norway (not to the Baltic), was 

 not attended with ani/ expense either to this or any other department 

 of government. The fact is simply this : — the Comet steam 

 vessel having been ordered to proceed to Heligoland at the 

 express request of the King of Denmark, for the purpose of 

 fixing with precision, by means of numerous chronometers, the 

 longitude of that island, in order to connect the Danish with the 

 British survey ; and the Board of Longitude having recommended 

 that the voyage should be extended as far as the Raze of Nor- 

 way, for the purpose of ascertaining the longitude of that 

 important point, Sir Humphry Davy volunteered to proceed in 

 her, at his own expense, to enable him to attend in person to 

 certain experiments which he was desirous of making on the 

 action of sea water on the copper of a vessel passing rapidly 

 through that medium. 



If any illiberal construction should have been conveyed to the 

 public, as your note would seem to imply, you are at liberty to 

 make use of this reply in any way you may deem fit. 

 I am, my dear Sir, very sincerely yours, 



John Barrow. 



J. G. Children, Esq. 



Verbum non amplius addam. 



Article XI. 



J. G. C. 



Inquiries respecting the Geological Relations of the Beds 

 between the Chalk and the Purbeck Limestone in the South- 

 east of England. Bv William Henry Fitton, MD. FRS. 

 MGS. &c. (With a Plate.) 



I. The geological relations of the beds of sand and clay which 

 are interposed between the chalk and the Purbeck limestone 

 have been of late the subject of considerable discussion ; and 

 various opinions have been formed respecting the difference of 

 structure supposed to exist in the two principal tracts, where 

 this part of the British series of strata is visible upon the coast, 

 namely the southern shore of the Isle of Wight, and the space 

 between the chalk cliffs near Folkestone and at Beachy Head. 

 Nothing can more strongly show the necessity of further in- 

 formation upon this subject, than the discrepancy in the 

 accounts of these two districts, and the general obscurity of all 



