368 



January 28, 1836. 

 RODERICK IMPEY MURCHISON, Esq., V.P., in the Chair. 



William Clark, M.D.; and Francis Marcet, Esq., were elected 

 Fellows of the Society. 



A paper was read, entitled, " Discussion of Tide Observations 

 made at Liverpool." By J. W. Lubbock, Esq., F.R.S. 



The chief purpose which the author has in view in presenting the 

 tables accompanying this paper, which are a continuation of those 

 published in the Philosophical Transactions for 1835, and are 

 founded on the observations instituted by Mr. Hutchinson at Liver- 

 pool, is to exhibit the diurnal inequality in the height of high water, 

 which is scarcely sensible in the river Thames, but which at Liver- 

 pool amounts to more than a foot. The diurnal inequality in the 

 interval appears to be insensible. 



The author has farther ascertained that Bernouilli's formulae ex- 

 pressing the height of the tide, deduced from his theory of the tides, 

 present a very remarkable accordance with observation. 



February 4, 1836. 

 SIR JOHN RENN1E, Km., Vice-President, in the Chair. 



George William Drory, Esq. ; Robert Edmund Grant, M.D. ; and 

 John Dillwyn Llewelyn, Esq. ; were elected Fellows of the Society. 



" Geometrical investigations concerning the Phaenomena of Ter- 

 restrial Magnetism : Second Series,— On the number of points at 

 which a magnetic needle can take a position vertical to the Earth's 

 surface." By Thomas Stephens Davies, Esq., F.R.S. Lond. and 

 Edin., F.R.A.S., of the Royal Military Academy, Woolwich. 



This paper is intended as a continuation of the one by the same 

 author published in the last volume of the Philosophical Transac- 

 tions; in which it was proposed to investigate the mathematical 

 consequences of the hypothesis of the earth being a magnet with 

 two poles, or centres of force, situated anywhere either within, or 

 at the surface, and of equal intensity, but of contrary characters : 

 with the ultimate view of verifying this hypothesis by comparing its 

 results, so deduced, with the phaenomena furnished by observation. 



In his former paper the author had shown that on this hypothesis 

 the magnetic equator, or the locus of the points at which the mag- 

 netic needle takes a horizontal position, is one single and continuous 

 line on the surface of the earth. In this paper his object is to prove 

 that there are always two, and never more than two, points at the 

 earth's surface, at which the needle takes a position vertical to the 

 horizon. 



At the close of his former paper the author had deduced the 

 equation of the curve of verticity, that is, of the curve at any point 



