98 Progress in Science. (January, 
by ring. The successive rings are bolted together, and sheet-lead is inserted 
between the planed faces of the flanges, while the annular space between the 
rings and the wall of the pit is filled in with concrete. The water is then 
pumped out of the pit, and additional security is given to the tubbing by 
cutting a lower seat, and building up a few lengths of tubbing, tightly wedged 
under the moss-box. By this ingenious system several pits have already been 
sunk, safely and successfully, through very dangerous ground. 
In spite of the spread of scientific knowledge, the aid which geology is 
capable of lending to the miner appears still to be too often ignored. One of 
the most glaring instances of unscientific mining has recently been recorded 
by Mr. Bristow, F.R.S. During the prosecution of his duties on the Geologicat 
Survey, he lately came upon a spot near Easton, in Somersetshire, where a 
shaft, with steam winding machinery in full operation, was being sunk in the 
vain hope of reaching coal at a depth of several thousand feet below the lowest 
strata of the true coal measures. Commenced in the lower limestone shales, 
the shaft had entered the old red sandstone, which it penetrated to the depth 
of 112 yards—every yard carrying the explorers so much further from the 
obje@ of their search. The want of scientific knowledge 1s nowhere more 
strikingly seen than in such futile experiments, which can only result in the 
useless expenditure of capital and in keen disappointment to the speculators. 
Some remarks on the prospeé of finding coal to the south of the Mendips 
have been contributed to the ‘‘ Geological Magazine,”’ by Messrs. Bristow and 
H. B. Woodward; and, in the same journal, Mr. S. Sharp has cited several 
instances of sinking for coal in Northamptonshire almost as absurd as that at 
Easton. In Northamptonshire, however, the borings have been made in 
oolitic rocks, beneath which the coal, if it exist at all, must be hidden at 
depths almost unattainable. Yet a proposal has been recently made to renew 
workings in a shaft which was sunk several years ago at Kingsthorpe, near 
Northampton. This shaft, after passing through the great oolite, inferior 
oolite, and lias, entered the new red sandstone, and eventually attained a 
depth of 967 feet from the surface. The project was then abandoned, but 
£30,000 had already been expended upon the workings. Mr. Sharp now 
calculates that workable coal cannot be expected to occur at less than 4000 feet 
from the bottom of the present shaft, thus making a total depth of about 
5000 feet from the surface. Still, this undertaking, unpromising as it appears 
to the geologist, is not without its supporters among unscientific speculators. 
As acontrast to these examples of ill-dire@ed energy, we may point to the 
results which have recently rewarded the spirited enterprise of Mr. J. C. 
Dawes, who for many years past has been exploring the borders of the South 
Staffordshire coal-field. It appears that after seven years’ search, at a cost of 
about £20,000, he has now discovered at the Hales Owen workings a portion 
of the Staffordshire thick coal, about 14 feet in thickness. 
During the past quarter, the Colliery Inspectors have issued their Reports 
for 1870. These reports may be advantageously compared with the corre- 
sponding documents for the previous year. Thus, in 1869, there were 
108,000,000 tons of coal raised in Great Britain by 345,446 colliers, whilst in 
1870 the production rose to 113,000,000 tons, and gave employment to 350,894 
miners. Yet the total number of separate accidents in 1869 amounted to 854, 
and resulted in 1116 deaths; but in 1870, notwithstanding the greater activity, 
there were only 830 accidents, resulting in the loss of ggt lives. In other 
words, one life was lost for every 99,777 tons of coal raised in 1869; but in 
1870 not less than 113,900 tons were raised for every life sacrificed. During 
1870 there were 56 explosions of fire-damp, whereby 185 deaths occurred; 
whilt in the previous year, with only 48 explosions, not fewer than 257 lives 
were lost. It would be difficult to carry the analysis of these reports further 
without introducing tabular statements unsuited to the pages of this journal. 
In the iron-stone mines which are under government inspection, there 
occurred, during the year 1870, 51 accidents, resulting in 55 deaths. In 
addition to the statistical information which these official reports contain, 
