1826.] Proceedings of Philosophical Societies. 141 



add, however, that owing to a combination of untoward cir- 

 cumstances, which no foresight or exertion on the part of Capt. 

 Sabine or myself could possibly have led us to calculate on, or 

 enabled us to prevent, and which the n)Ost zealous endeavours 

 on that of Col. Bonne failed to remedy, no less than 8 out of 

 the 12 nights' observations were totally lost, as to any result they 

 might have afforded, and the remainder materially crippled ; so 

 that a much more moderate estimate of the value of our tinal 

 result must be formed, than would otherwise have been justified. 

 Still it is satisfactory to be able to add (such is the excellence 

 of the method), that a result on which considerable reliance can 

 be placed, may be derived from the assemblage of the observa- 

 tions of these four nights ; and when it is stated that this result 

 appears not very likely to be the tenth of a second in error, 

 and extremely unlikely to prove erroneous to twice that amount^ 

 it will perhaps be allowed that, under such circumstances, more 

 could hardly be expected." 



The difference of the meridians by these observations is 

 9'"2P-6. 



IX, Observations on the Poison of the Common Toad; by John 

 Davy, MD. FRS. 



For an abstract of this paper, see Annals for Feb. p. 137; and 

 for some remarks on the subject of it, see the number for April, 

 p. 277. r 



X. On the Magnetizing Power of the more refrangible Solar 

 Rays; by Mrs. M. Somerville : communicated by W. Somer- 

 ville, MD. FRS. 



A report of the contents of this paper will be found in the 

 Annals for March, p. 224. i 



XL On the Mutual Action of Sulphuric Acid and Naphtha^ 

 line, and on a new Acid produced ; by M. Faraday, FRS. &c. 



We shall probably give this paper in a future number ; in the 

 mean time we may refer to that for March, p. 226, for some 

 account of the facts it describes. E. W. B. 



{To be continued} 



Article XI. 



Proceedings of Philosophical Societies » 



ASTRONOMICAL SOCIETY. 



May 12. — A paper, by the Astronomer Royal, was read, con- 

 taining an explanation of the method of observing with the two 

 mural circles, as practised at present at the Royal Observatory. 

 The principal object of the method explained in this paper is to 

 diminish as much as possible the inaccuracies occasioned, even 

 in the most perfect instrument, by rapid and partial changes of 



