Geological Society. 79 



the current. The point at which this phenomenon takes place is 

 called the magnetic breaking point. A further increase of the cur- 

 rent was attended with a rapid decrease of this ratio as the satura- 

 tion of the har was approached. 



The total change of magnetic condition by reversal of the cur- 

 rent, minus the magnetic set, is found to be nearlj' proportional to 

 the intensity of the current. 



Results of exactly similar character were obtained by the use of 

 an electro-magnet, consisting of a bar of hard steel i of an inch in 

 diameter and 7| inches long. 



In conclusion, the author points out the striking and instructive 

 analogy which exists between the above phsenomena and those of 

 the set of materials as exhibited by Professor Hodgkinson, who, in 

 his admirable researches, has proved that the set, or permanent 

 change of figure, in any beam is proportional to the square of the 

 pressure to which it has been exposed. 



GEOLOGICAL SOCIETY. 



November 5, 1855.— Mr. ^^f. J. Hamilton, President, in the 



Chair. 

 The following communications were read : — 



1 . " On the Coal of the North-western Districts of Asia Minor." 

 By Mr. H. Poole ; communicated by the Foreign Office. 



Mr. Poole, in his reports to the Government on the result of his 

 journey to Asia Minor, to examine into the probability of workable 

 coal being found in the country near Brussa and Ghio (Bithynia), in 

 which coal had been reported to occur, states that he travelled from 

 Ghio to the Lake Ascania, and around its shore, without finding any 

 trace of coal ; then from Yallova inland to Ortokoi, with like result. 

 He next went from Yallova westwards along the coast as far as Kor- 

 nikoi, where a bed of lignite, 9 inches thick, was worked to some 

 extent by the Armenians four years since ; thence he went inland to 

 Sulmanl'i without seeing any indications of coal. In consequence of 

 rumours of the existence of coal near the Lake of Apollonia, Mr. 

 Poole travelled round that lake, but met with none. Mr. Poole next 

 went from Yallova south-eastwardly to Tchougnoorkoi, where lignite, 

 varying from 1 to 4 feet in thickness, and dipping at a high angle, 

 has been also worked by the Armenians. This lignite is of no pro- 

 mise. Another excursion was to the Lake Sabandji, where a thin 

 scam of lignite crossing the road on the south of the lake, and a lig- 

 nite at Ag Sophe, to the east of the lake, were visited. Nowhere did 

 Mr. Poole find proof of the existence of good workable coal in the 

 districts visited. 



2. " On the newer Tertiary Deposits of the Sussex Coast." By 

 Mr. R. Godwin Austen, F.G.S. 



From Brighton, westwards, between the chalk hills and the sea, 

 the surface of the country is formed, first, by a raised terrace of "red 

 gravels," lying on the sloping base of the chalk hills, and on the old 

 tertiary deposits ; secondly, the gravels of the Chichester levels, or 



