The Rev. S. Haughton on the Tides of the Arctic Seas. 149 



November 27. — Major-General Sabine, President, in the Chair. 



The following communications were read : — 



"Dynamical Problems regarding Elastic Spheroidal Shells and 

 Spheroids of Incompressible Liquid." By Professor William Thom- 

 son, F.R.S. 



" On the Exact Form and Motion of Waves at and near the Surface 

 of Deep Water." By Professor W. J. Macquorn Rankine, C.E., 

 F.R.S., &c. See Phil. Mag. vol. xxiv. p. 420. 



"On the Tides of the Arctic Seas. — Part II. The Semidiurnal 

 Tides of Port Leopold, North Somerset." By the Rev. Samuel 

 Haughton, M.A., F.R.S,, &c. 



The first part of the author's researches on the Tides of the Arctic 

 Seas was forwarded to the Royal Society hi November 1861, and 

 contained the discussion of the Diurnal Tides of Port Leopold. In 

 the present communication the Semidiurnal Tides of the same port 

 are discussed, and the following results obtained. The eccentricity 

 of the moon's orbit is calculated from the parallactic inequality, and 

 found to be 0'5303. 



The solitidal interval is 56 m . 



The lunitidal interval 4 h 54 m . 



The ratio of the solar to the lunar coefficient is found to be 0'3956. 



The mass of the moon j^\. 



And the depth of the Atlantic is calculated from received tidal 

 theories. The most probable results are found to be, — 



From semidiurnal tidal intervals . . 3'529 miles. 

 From diurnal coefficients .... 3" 690 „ 



There are other values of the depth of the sea, much greater than 

 these, which follow from other considerations of the tidal theory ; 

 and the author is unable to explain why theory should give results 

 so different. The preceding, however, he believes to be most in 

 accordance with facts. 



" On the Action of Chloride of Iodine on Iodide of Ethylene and 

 Propylene Gas." — Second Notice. By Maxwell Simpson, M.B., 

 F.R.S. 



" On certain Developable Surfaces." By A. Cayley, Esq. 



December 11. — Major-General Sabine, President, in the Chair. 



The following communications were read: — 

 "Observations on several Mineral Substances, including their 

 Analysis, &c." By Dr. T. L. Phipson, F.C.S. 



" On the Strains in the Interior of Beams." By George Biddell 

 Airy, F.R.S., Astronomer Royal. 



The author states that he had long desired to possess a theory 

 which should enable him to compute numerically the strains on 

 every point in the interior of a beam or girder, but that no memoirs 

 or treatises had given him the least assistance. He had therefore 

 constructed a theory which solves completely the problems for 

 which he wanted it, and which appears to admit of application at 

 least to all ordinary cases. 



