1824.] Proceedings of Philosophical Societies. 229 



" P. S. I may here take the opportunity of correcting an 

 error in the " Account of Experiments for determining the 

 Variation in the Length of the Pendulum vibrating Seconds at 

 the principal Stations of the Trigonometrical Survey of Great 

 Britain." 



" In the first series of observations made with the repeating 

 circle for the latitude of Clifton, 1' 41'6" has been applied as the 

 correction for the level instead of 141*6" = 2" 21-6". The 

 resulting latitude, when the proper correction is made, is 

 53° 27' 44-94" instead of 53° 27' 4094", and the greatest differ- 

 ence between the five independent latitudes of Clifton 3-48" 

 instead of 5-24"." 



XXIII. On the Daily Variation of the Horizontal and Dipping 

 Needles. By Peter Barlow, Esq. FRS. 



An abstract of this paper will be found in the present number 

 of the Annals, at p. 163. 



XXIV. On the Diurnal Deviations of the Horizontal Needle 

 whenunder the Influence of Magnets. By Samuel Hunter Chris- 

 tie, Esq. MA. Fellow of the Cambridge Philosophical Society: 

 of the Royal Military Academy. Communicated by Sir Hum- 

 phry Davy. 



Our present limits will not permit us to give any account of 

 this extended paper, occupying 50 pages ; but we shall probably 

 devote a separate article to that purpose. 



XXV. On Fossil Shells. By Lewis Weston Dillwyn, Esq. 

 FRS. In a Letter to Sir H. Davy. 



This paper we have reprinted entire at p. 177 



(To be continued.) 



Article XV. 



Proceedings of Philosophical Societies. 



KOYAL SOCIETY. 



Jan. 15. — Messrs. J. H. Vivian, and Michael Faraday, were 

 respectively admitted Fellows of the Society; and the reading 

 of Messrs. Herschel and South's " Observations on the Posi- 

 tions and Distances of Three Hundred and Eighty Double and 

 Triple Fixed Stars," was resumed and concluded. 



Jan. 22. — Dr. C. Scudamore was admitted a Fellow of the 

 Society ; and the following paper was read : 



" On a Mode of preventing the Corrosion of Copper-Sheath- 

 ing, by Sea-Water, in Ships of War, and other Ships." By Sir 

 Humphry Davy, Bart. PES. 



The attention of the President having been drawn to this sub- 

 ject by the Commissioners of the Navy Board, he instituted a 



