PROCEEDINGS, 1859 — 1870. 
335 
a platinum point which estabhshes communication of the electric 
current. By placing this instrument near the roof of a colliery the 
presence of hre-damp may be detected with the greatest nicety, and 
communication made with an electric bell, which at once gives 
warning of its presence. 
The Rev. John S. Tute, in a paper on the Geology of the country 
near Ripon, described several rocks occurring in the neighbour- 
hood of Ripon, comprising the new Red Sandstone and the Magnesian 
Limestone. He drew attention to the sparry cavities so characteristic 
of the latter, and inferred that they had probably arisen from the 
decay of organic remains. At Aldfield a considerable number of 
fossil mollusca had been obtained. Below these beds was the Red 
Grit of the Cayton Gill Beds, the latter at Hampsthwaite and other 
places being highly fossiliferous. Below these are the Coal measures. 
Ripon is built upon a thick bed of glacial drift, which lies in a trough 
between the Magnesian Limestone and the Xew^ Red Sandstone. 
The glacial beds are deposited in the bottoms and on the sides of 
valleys which were excavated before the glacial period. Eastward the 
drift passes imperceptibly into the general superficial deposits of the 
Vale of York. On the sides of the valley of the Ure extensive 
beds of gravel are located, which were probably derived by the action 
of water from the glacial beds. 
At the same meeting a paper was contributed on the Geology of 
parts of Yorkshire and Westmoreland, by Prof. T. ^IcKenny Hughes, 
M.A., of Her ^Majesty's Geological Survey, in which he called atten- 
tion to points of special interest, some of wdiich required still further 
working out. The mountainous districts of Yorkshire, comprising 
Ligleborough, Whernside, and Penyghent consist chiefly of Yoredale 
Rocks, capped by Millstone Grit, resting on a great plateau of 
Mountain Limestone. The great Craven faults bring down the 
Mountain Limestone against the Silurian Rocks, and the higher 
formations against the ]Mountain Limestone. Mr. Hughes considers 
that the Green Slates and Coniston Limestone at Chapel-le-dale, 
Kingsdale, and Horton must be referred to the Lower Silurians, and 
are the equivalents of the Carradoc Sandstone and Bala Limestone of 
Wales. These rocks were hardened and upheaved, and their edges 
