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the writer is acquainted, I shall now endeavour to recapitu- 
late some of the most improved appliances and inventions 
used in sinking, developing, and working mines. The in- 
vention of M. Chaudron, a Belgian engineer, enables shafts 
to be sunk through water-bearing strata, where otherwise 
the operation would not be possible, except at a ruinous 
expenditure of time and capital. The difficulty which this 
contrivance is intended to overcome is one that must increase 
as our explorations for coal extend under the Magnesian 
Limestone or Permian Rocks, where such large feeders of 
water usually exist. A remarkable instance of this kind is 
furnished by the recent abandonment, for the present at any 
rate, of the mining at Whitburn, in Dui'ham, intended to 
sink through the limestone nearer to the sea than has been 
attempted previously. Ten thousand gallons of water per 
minute were raised, down to a depth of 20 yards, beyond 
which the shaft could not be continued, the circumstances 
indicating that the water from the sea passed into the shaft 
through the fissures of the limestone. The fate of this enter- 
prise alone, shows the importance of an efficient and econo- 
mical arrangement for sinking through rocks containing 
such large quantities of water. 
The invention of M. Chaudron may be briefly described 
as follows : — First, an artificial shaft is built on the surface, 
of the same size as the proposed shaft is intended to be, and 
sufficiently high to prevent the water as it comes in from 
overflowing. By this means the water is impounded, and 
its movements stopped, thereby avoiding the usual difficulties 
arising from shifting or loose sand. The process of boring 
under water then proceeds by means of a cutter, so con- 
structed as to cut the ground ready for excavation and the 
size of the shaft required. The debris is extracted by means 
of an ingenious arrangement, whereby the difficulty of col- 
lecting it, to bring up to the surface is overcome ; and a shaft 
