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is sunk in precisely the same manner as a bore-hole is made, 
standi no: full of water, and unlined until the bottom of the 
shaft is reached. The tubbing is then lowered into the 
shaft. It is finished at the bottom with a telescopic joint, 
whereby a water-tight junction with the rock on which it 
rests is effectually secured. 
If any person wishes to obtain a more detailed knowledge 
of this improved invention, the writer would refer him to 
the very able paper by Mr. Warrington Smyth, in vol. 20 
of " The Transactions of the North of England Institute of 
Mining Engineers ;" and if desirous to see the process in 
actual working in England, he may do so at the works of ' 
the Cannock and Huntingdon CoUiery Company, near 
Walsall, South Staffordshire. 
Another process of sinking through water-bearing strata 
is that designed by J. T. Woodhouse, Esq., Civil and Mining 
Engineer, Derby, and carried out by him at Bagillt Colliery, 
North Wales, which is sunk in the bed of the River Dee. 
During the sinking operations, which the writer had the 
pleasure of inspecting, the present Resident Engineer, Mr. 
Arnold Lupton, C.E., with great mechanical ability, carefulty 
explained to him every detail of the operation, which may 
be briefly described as follows : — The first shaft was sunk 
by the pneumatic process, through about 80 feet of quick- 
sand, and was done partly by means of a vertical cast-iron 
tube, 6 feet in diameter, and moved about the shaft, which 
was 20 feet in diameter, by machinery constructed for that 
purpose ; the pressure of aii* inside the tube keeping out the 
water, while a double trap-door at the top provided for the 
passage of the excavated material, and the ingress and egress 
of the workmen. During a great part of the sinking, the 
work was done entirely by divers. The second shaft, 11 
feet in diameter, was sunk through the sand entirely by the 
pneumatic system. A cast-iron cy finder, 13 feet in diameter. 
