378 Geological Society : — 



May 1. — Communications were made by Mr. Harry Seeley — 



1. "On the Cambridge Greensand. — Part I. The Rock and its 

 Origin." 



2. " On the Gravel and Drift of the Fenland. — Part II. Theory." 



May 15. — A communication was made by Professor Churchill 

 Babington " On the Coinage of England before the Norman Con- 

 quest." 



May 29. — A paper was read by Mr. Todhunter " On the Method 

 of Least Squares." 



The object of this communication is principally to demonstrate a 

 very remarkable result which Laplace enunciated, without demon- 

 stration, in the first Supplement to his work on ' Probabilities.' An 

 exposition is also given of the process adopted by Laplace for inves- 

 tigating the method of least squares. Laplace's process is genera- 

 lized and extended ; and results which he obtained for the case of 

 two elements are shown to hold for any number of elements. The 

 mathematical part of the investigation consists chiefly in the evolu- 

 tion of certain definite multiple integrals. 



GEOLOGICAL SOCIETY. 



[Continued from p. 159.] 



May 24, 1865.— Dr. E. Meryon, Vice-President, in the Chair. 



The following communications were read : — 



1. " Additional Observations on the Raised Beach of Sangatte, 

 with reference to the date of the English Channel, and the presence 

 of Loess in the Cliff-section." By Joseph Prestwich, Esq., F.R.S., 

 Treas. G.S. 



In his paper on the Loess and Quaternary beds of the North of 

 France and South-east of England, Mr. Prestwich expressed an 

 opinion that the break in the land between France and England 

 was not the result of the last geological change, but that the channel 

 existed at the period of the formation of the Low-level gravels of the 

 Somme and Thames Valleys, and probably at that of the High-level 

 gravels. During a recent visit to the Sangatte Raised Beach, the 

 author recognized fragments of chert in the shingle and associated 

 sands, which he inferred were derived from the Lower Cretaceous 

 strata ; associated with them were fragments from the Oolitic series 

 of the Boulonnais and two pebbles of red granite, probably from the 

 Cotentin. 



These facts seemed to the author to add much probability to the 

 existence of a channel open to the westward, and extending between 

 France and England, anterior to the Low- and possibly to the 

 High-level Valley-gravel period. Above the raised beach occurs a 

 mass of chalk- and flint-rubble, with beds of loam, from 20 to 80 feet 

 thick, and containing Land-shells. Mr. Prestwich considered this 

 accumulation analogous to the Loess, which it resembles in general 



