1872.] (97) 
PROGRESS IN SCIENCE. 
MINING. 
AmonG the many difficulties with which the miner has to contend, some of the 
gravest are those which beset his attempts to carry shafts through water- 
bearing strata. It unfortunately happens, however, that the Permian beds, 
which extend over large areas of our coal-measures, are often so highly 
charged with water that the operation of piercing them in sinking a pit-shaft 
becomes a task not only ruinously expensive, but fraught with the greatest 
danger to life and limb. Nevertheless, the future development of our coal- 
fields must depend in great measure upon the possibility of winning coal from 
beneath these newer rocks; and, consequently, unusual interest attaches to 
any improvements which tend to reduce the difficulties of such work toa 
minimum. For some time past Messrs. Kind and Chaudron have been suc- 
cessfully engaged in boring deep shafts through watery ground; anda valuable 
account of their system as at present practised in Belgium has been lately 
given to the North of England Institute of Mining Engineers, by Mr. Warington 
W. Smyth, F.R.S. The peculiarity of this process consists in sinking the 
pit @ niveau plein, that is to say, in carrying on the boring while the water is 
“at full level” in the shaft. By this means no pumping machinery is 
needed during the boring, and hence one of the chief items of expense 
is eliminated, whilst safety to the workmen is ensured by conduéting the 
operation at or near the surface, after the manner of boring an Artesian well. 
Mr. Smyth’s observations were made on a pair of pits now being sunk by 
this process in the concession of Maurage, on the north rise of the Bassin du 
Centre, in Belgium. The coal-measures are here overlain by a considerable 
thickness of cretaceous and tertiary strata, consisting chiefly of sands, marls, 
and chalk, which in the upper part hold a great amount of water. The 
foundation of the iron tubbing in these pits is to be fixed at a depth of 636 feet. 
The four or five men employed in sinking each shaft work upon a platform 
about 16 feet below the surface. At this working floor the shaft is nearly 
1g feet in diameter; but immediately below, it contracts to 15*4 feet, and is 
carried down of this size to the water-level, which is situated at a depth of 
about 98 feet. No attempt is made to remove the water until the dangerous 
ground is pierced through; but the work is carried on by boring, while the 
shaft—which is nothing more than a gigantic bore-hole—remains filled with 
water up to its natural level. The boring is effected in two or more stages: 
during the first, a cylindrical hole is made about 5 feet in diameter, 
and when this has advanced to a depth of 30 or 4o feet, the upper part 
is enlarged to the full diameter of the pit. The cutting-tool, or trépan, 
consists of a horizontal bar of wrought-iron, armed upon its lower surface 
with steel teeth, and attached to thick rods of pine, which are screwed 
together and fastened at the upper end, by a strong flat chain, to one 
extremity of a simple lever, the other end of which has dire@& conneéction 
with the piston-rod of a steam-engine at the surface. By admitting 
steam above the piston, that end of the lever is depressed, whilst the other end 
carrying the rods is elevated; the fall of the boring-tools is secured by their 
own weight. The cutter for the large bore weighs about 16 tons, while 
that for the smaller hole varies according to the nature of the ground; but in 
piercing hard rock—such as flint—may amount to 8 tons. When the watery 
measures are pierced, the iron tubbing is let down into its place. This 
tubbing is made in short lengths, or rings, each with a flange above and below. 
The bottom flange of the lowest ring is securely seated on a bed cut in 
water-tight ground, and is surrounded on the outside by a wall of tightly- 
pressed moss. Upon this moss, as upon a cushion, rests a ring, which slides 
over the previous piece, and upon this sliding tube the tubbing is built up ring 
VOL. II. (N.S.) o 
