PROCEEDINGS OF GEOLOGICAL SOCIETIES. 
211 
The author of the paper divided the superficial deposits of the district into 
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 followinj^ order. 
'1. Drift sand 
2. Peat bed 
3. Bluish clay 
4. Submarine Eorest-bed 
5. Bluish clay 
6. Submarine Torest-bed 
Post-Glacial Deposits 
C 7. Upper Drift sand 
Glacial Deposits < 8. Boulder clay 
(.9. Lower Driftsand and gravel. 
With tlie 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 land 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 nortli, 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 luid 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 On the 
the Explosion at Hetton Colliery," — in which that gentleman mniutely detailed 
the circumstances of the melancholy explosion there on the 20th December 
previous. A discussion followed, in which the Chairman, Professor lioscoe, 
Mr. Booth, Professor Calvert, Mr. Knowles, 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 liim, like a thief in the night, without any misleading as 
to where it is likely to be present or absent. In a work lately publisliecT in 
America — " A practical treatise on Coal, Petroleum, and other Distilled Oils, 
by Abraham Gesner, M.D., E.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, \vhere 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 accordmgly 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. 
