Sept. 15, 1870] 
NATURE 
by Mr. John Jones, F.G.S., the Secretary to the Institute 
and to the North of England Iron Trade. 
_ We now proceed to give a brief notice of the papers 
read at the recent meeting at Merthyr :— 
_ I. “On the Geological Features of the South Wales 
Coal-Field.” By Mr. William Adams, Cardiff. In this 
paper, which was of special interest to such of the mem- 
bers as were strangers to the district, the author traced 
the history of our knowledge regarding the position, 
nature, and extent of the coal deposits which have given 
such an industrial importance to South Wales. Attention 
was directed to this coal-field as far back as the year 1570, 
bat the essay itself did not appear till the year 1796, when 
it was published in the Camdrian Register. Since that 
time many persons have devoted attention to the subject, 
including Edward Llwyd (1697, “ Philosophical Transac- 
tions,” 1712) ; Edward Martin (Royal Society, 22nd May, 
1806); Buckland and Conybeare (1822, ‘‘ Geological 
Transactions,” vol. 1.); Robert Bakewell (1833); Sir 
Henry J. De la Béche (1846, “‘Memoirs of the Geological 
Survey,” vol.i.); Mr. Hussey Vivian, M.P.(1860); and Mr. 
Hull (1861, “ Coal Fields of Great Britain”). According 
to Mr. Adams, the South Wales coal-field extends from 
Blaenavon and Pont-y-pool, on the east, to St. Bride’s 
Bay, in Pembrokeshire, on the west, a distance of about 
ninety miles ; while its breadth varies from about sixteen 
miles on the east to about four miles in the extreme 
west. The superficial area is given as low as 906 
square miles (Hull), and as high as 1,200 square miles ; 
but Mr. Adams puts it at 9374 square miles, or 
600,000 acres. Taking the average thickness at sixty 
feet, as given by Mr. Vivian, M.P., one of the Royal Com- 
missioners on the Coal Supply, and deducting one-third 
for loss in working, for faults, waste, &c., the extent of coal 
is 36,000,000,000 tons. The author pointed out the qualities 
of the mineral in different parts of the coal-field. On the 
east it is bituminous, and makes a very superior coke ; it 
continues so to Rhymney; at Dowlais it becomes free- 
burning ; at Cyfarthfa it begins to take on the characters of 
anthracite ; and further westward the coal becomes more 
and more distinctly anthracitic, until, in the west, it 
becomes so pure that it is worked for drying hops and malt 
and for distilling purposes, &c. Within the field there are 
obtained the well-known steam coals of Merthyr, and the 
Aberdare and Rhondda valleys. Argillaceous ironstones 
are very abundant and good. They are interstratified 
with the coal, and have an aggregate thickness of from 
sixty to seventy inches or upwards, and until about thirty 
years ago they yielded practically all the iron which was 
smelted in Wales. Since then the deficiency for the iron- 
works has been drawn from other British and foreign 
mines. The pig iron made in South Wales in 1854, ac- 
cording to Mr. Hunt’s “ Mineral Statistics,” was 750,000 
tons, and the coal raised in the same year was 8,500,000 
tons, while the amount raised in 1868 was 13,210,000 tons, 
Owing to the remarkable denudation in the valleys of the 
district, the lowest seams of coal can be won by pits of 
less than 1,000 yards in depth throughout about two- 
thirds of the basin. A greater depth may be required 
west of the Vale of Neath and onto Llanelly, where the 
deepest part of the basin occurs. Throughout the coal- 
field there are faults, running north-west and south-east, 
which give a vertical displacement of 250 or 300 yards ; 
and there are others running east and west which give a 
displacement of from 400 to 500 yards ; and one is said to 
occur in Pembrokeshire which is equal to a displace- 
ment of upwards of 666 yards. The deepest pits are 
those which reach down to the nine-feet seam; their 
depth varies from 304 to 435 yards. In the coal-field 
there is found some of the best fire-clay known ; there is 
also a remarkable siliceous stone, which is used to make 
the well-known refractory fire-bricks called Dinas brick. 
Alum shales occur, and, near Pont-y-pool, a rich oil 
shale is found, which yields on distillation from fifty to 
395 
fifty-five gallons of crude oil, of which twelve to fifteen 
per cent. may be separated as mineral turpentine. Mr, 
Adams also referred to the extent and distribution of the 
mountain limestone—so useful as a flux in smelting the 
ironstone—and in the fossils which the coal measures of 
the district contain ; and, in concluding his very valuable 
paper, he also strongly urged the desirability of a new 
geological survey on the six-inch scale being made. 
In the course of a short discussion which followed the 
reading of the paper, several interesting points were raised, 
more especially in reference to the effects of the faults in 
changing the character of the coal. 
II. “On Pumping and Winding Machinery.” By Mr, 
G. C. Pearce, Cyfarthfa Iron Works. This paper em- 
braced a short description of the pumping and winding 
machinery lately erected at the Castle Pit, near Merthyr, 
the property of Mr. R. T. Crawshay. Notwithstanding 
the shortness of the paper, it would be difficult to givea 
satisfactory description of the machinery in the form of 
an abstract, especially without illustrations. But a few 
facts may be mentioned. The pit is 333 yards in depth 
to the bottom of the sump, but the pumps only raise the 
water 279 yards, where there is an adit. Itis of an oval 
form, 22 feet 8 inches long by 12 fcet wide, with a brattice 
dividing the winding parts from the pumps ; and it is all 
built with brick throughout. ‘lie total cost of the 
machinery and the sinking of the pit was about 30,000/., 
the winding engine alone costing above 4,000/, 
In the afternoon of Tuesday the Castle Pit was visited 
by the members of the Institute, many of whom were much 
struck with the gigantic and ingenious character of the 
machinery erected by Mr. Pearce. 
Mr. E. A. Cowper, C.E., F.R.S., followed with some ob- 
servations in reference to the working of steam for pump- 
ing, winding, and blowing engines; but no discussion 
ensued. 
III. “On the Condition of Carbon and Silicon in Iron 
and Steel.” By Mr. George J. Snelus, Associate of the 
Royal School of Mines, chemist at Dowlais Iron Works, 
This paper was of considerable length and very elaborate. 
It contained the results of a long course of experimental 
inquiry, instituted with a view to determine the conditions 
in which the two non-metallic bodies, carbon and silicon, 
exist in iron and steel. Dr. Percy had said in his cele- 
brated work, “ Iron and Steel,” that not a trace of graphite 
could be detached by the point of a penknife from the 
fractured surface of highly graphitic iron ; but Mr. Snelus 
had proved the incorrectness of this statement by ex- 
amining some pig iron which had cooled slowly under a 
mass of slag, and which had in consequence very large 
crystals. From the surfaces of these crystals the graphite 
could not only be separated with the point of a penknife, 
but even with the finger-nail ; and when the graphite was 
removed the iron underneath rapidly rusted in a damp 
atmosphere. The same thing was afterwards observed 
with the fractured surface of Bessemer pig-iron, and the 
scales removed were found on further examination to be 
pure carbon. By pulverising pig-iron and then using the 
magnet a considerable amount of graphite was separated, 
Other mechanical means were employed, and the same 
results were obtained. In spiegeleisen the carbon was 
found to be almost wholly combined. The author had 
never found as much as five per cent. of combined carbon 
in pig iron, although many analyses had been published in 
which the carbon was put down at evensix per cent. Mr. 
Snelus was not inclined to believe that there was any 
definite compound of carbon and iron but, he thought that 
the carbon was dissolved in the iron, the amount taken up 
by the molten iron varying according to several circum- 
stances. According to Mr. Snelus there is no pig iron 
that is destitute of silicon, and he had never met witha 
case in which either steel or wrought iron was totally free 
from it. (coud Bessemer and tool steel rarely contains 
more than two or three parts in 10,000, One part of 
