PROCEEDINGS OF GEOLOGICAL SOCIETIES. 



211 



'Post-Glacial Deposits' 



The author of the paper divided the superficial deposits of the district iuto 

 two well-marked divisions, viz., strata of bluish clay, with submarine forest- 

 beds, which repose on strata of sand, Boulder-clay, and gravel. If all the 

 members of these two divisions were present in one section, they would occur 

 in the following order. 



fl. Drift sand 



2. Peat bed 



3. Bluish clay 



4. Submarine Forest-bed 



5. Bluish clay 



6. Submarine Forest-bed 

 C7. Upper Drift sand 



Glacial Deposits < 8. Boulder clay 



(.9. Lower Drift sand and gravel. 



"With the exception of the upper and lower Drift sands (Nos. 7 and 9), all 

 these beds can be seen at Dove Point, on the Cheshire coast. 



Beneath the Liverpool Custom-house, an old laud surface, with the trunks of 

 trees, exists about forty feet below the level of the ordinary spring tides. A 

 similar bed occurs about two miles to the north, also on the Cheshire side of 

 the Mersey, below the bed of Woollasey Pool. 



The different degrees of subsidence in several localities, arises from the varying 

 elevation of the original land above the sea. When the lowest beds were sub- 

 merged the higher land-surfaces must have been above the level of the sea. 

 The author concluded that the whole district had subsided about fifty feet, but 

 that the greater part was prior to historical times. 



Manchester Geological Society. — At the Ordinary Meeting on the 29th 

 January, E. W. Binney, Esq., F.R.S., the Vice-President in the chair, there 

 was a very full attendance of members and scientific visitors from the neigh- 

 bourhood, great interest being manifested in Mr. Dickinson's paper -c On the 

 the Explosion at Hetton Colliery," — in which that gentleman minutely detailed 

 the circumstances of the melancholy explosion there on the 20th December 

 previous. A discussion followed, in which the Chairman, Professor Boscoe, 

 Mr. Booth, Professor Calvert, Mr. Knowies, Mr. Loveridge, and Mr. Dickinson 

 took part. 



The Chairman said that he considered it his duty to publicly contradict any 

 erroneous statement which he saw in print respecting fire-damp. Now this 

 invisible and intangible enemy is sufficiently dangerous to the coal-miner, often 

 coming suddenly upon him, Like a thief in the night, without any misleading as 

 to where it is likely to be present or absent. In a work lately published in 

 America — " A practical treatise on Coal, Petroleum, and other Distilled Oils, 

 by Abraham Gesner, M.D., F.G.S. — published by Bailliere — and having a con- 

 siderable circulation in this country, at p. 14, is the following—" In mines of 

 lignite and cannel coal, carbonic acid or choke-damp is almost the only gas 

 present." Seams of cannel coal, from being open-jointed, no doubt do sooner 

 allow the fire-damp to be drained from them than from seams of ordinary coal. 

 However, we who are acquainted with the Wigan district, where more cannel 

 is wrought than from any other mines in the world, on the one side, and those 

 of Dunkinfield on the other, know well that fire-damp is sadly too prevalent in 

 them, and accordingly thorough and efficient ventilation, aided by the use of 

 safety-lamps, is or ought to be in use in cannel, as well as coal-mines, if explo- 

 sions are to be prevented. 



