PROCEEDINGS 1849 — 1858. 
269 
spar, but occasioually actual crystals of felspar were found. This 
leads to the inference that the sandstones are the result of tlie decom- 
position of an older rock which contained these ingredients in large 
proportions, and the author is of opinion that that rock had been 
derived from the disintegration of coarse-grained gTanites. This 
opinion receives some proof from the ftict that he had found a few 
pebbles of undoubted granite, which are composed of quartz and fel- 
spar similar to the grit rocks. Besides the felspar there also occur 
pebbles of a fine-grained felspathic rock with a few laminae of mica, 
and rarer instances of white or brownish orthoclase felspar. The 
question then arises as to where the land would be situated from 
which this waste granite was obtained. j\Ir. Sorby, in a paper read 
at a previous meeting, had shown that the current which drifted the 
materials into the present resting-place came from the north-east, 
and therefore he was led to expect that the ancient land which fur- 
nished them lay in the same direction, and the nearest locality at 
present known from which they could have been derived is situated 
in Norway or Sweden, unless some south-westward prolongation of 
that country existed whose disintegration and removal has now given 
place to the North Sea. 
During the decade now under consideration, a large amount of 
attention was given to the ventilation of mines, and the circumstances 
attending colliery explosions. Government Inspectors had been 
appointed, who regularly subjected the mines to inspection, and it 
was hoped that their influence and recommendations would diminish 
the frequency and extent of disasters arising from the explosion of 
fire-damp in mines. Notwithstanding this, some very alarming 
explosions had occurred during the past few years, and had been 
the subject of investigation by men of acknowledged eminence 
in the scientific world. The Oaks Colliery, at Barnsley, which has 
been previously mentioned, was reported upon by Sir Henry de la 
Beche and Mr. Warrington W. Smythe, who had previously reported 
upon an explosion at Risca, in Monmouthshire ; Dr. Faraday and 
Sir Charles Lyell had presented a report on the explosion at Haswell, 
in Durham, in 1844 ; and Dr. Pla}^air on the one at Jarrow. These 
reports provided subject matter for much discussion on important 
