102 
MAGAZINE OF SCIENCE AND ART. 
coal will bo found capable of profitable development, 
and we may look forward to the time when competitors 
will spring up in districts hitherto scarcely known. 
Already I observe that a very important discovery has 
been made by Mr. Ilerhorn, the surveyor to the Aus¬ 
tralian Agricultural Company, he having brought to 
light an extensive field of iron ore of very rich quality, 
within four miles of Stroud, Port Stephens, so that I 
trust this will form but the first of a series of papers 
upon the same subject which may be read before this 
society. 
I now proceed to describe the progress made by the 
Fitz Roy Iron and Coal Company in this colony to¬ 
wards the working the rich beds of iron ore upon'their 
property, as the same will give you the opinion I have 
formed (after two careful surveys) of their capabilities 
of producing at a profitable rate* and in sufficient quan¬ 
tities, agood class of malleable iron. 
The Fitz Roy iron mine is situated at Mittagong, in 
the county of Camden, seventy-five miles from Sydney, 
on the Goulburn or Great Southern Road, at an‘el ova¬ 
tion of 2053 feet above the sea, from which it is distant 
at Wollongong, twenty-one miles. 
The mine, as visible to the eye, covers an area of 
about sixteen acres, and lies in a compact mass, on a 
gentle inclination at the head of a valley surrounded 
by a succession of undulating lands, flanked by lofty 
and precipitous ranges. 
The principal advantages which Mittagong possesses 
as a seat far the manufacture ot iron, is its proximity to 
a supply of coal of good quality, and the high road as 
well as the intended line of railway to Goulburn pass¬ 
ing through the property, and which when completed 
will place it within a journey of two hours from the 
metropolis. 
The ore is of peculiar richness and belongs to that 
class known as hydrated peroxide of iron, which is so 
profusely distributed over the United States. Accord¬ 
ing to the assay made by Mr. Hodgson, it contains 57 
per cent, of metal and one per cent, of manganese, the 
presence of which I should state will tend to" close the 
grain of the metal and improve its quality for both its 
bar iron aud steel making. It is in one enormous 
mass extending to a considerable depth, can be cheaply 
raised, and is practically exhaustless. The specimens 
before you this evening have been taken indiscrimi¬ 
nately from the surface of the mine. 
Little is as yet known of the conditions which pro¬ 
duce the distinctive qualities of iron manufactured from 
ores of different classes, and a wide field remains for 
investigation on this subject. But from all which I 
have seen and examined of the produce of this mine, it 
appears to me highly suitable for the manufacture of 
rail and bar iron in general, being tough and fibrous 
when cold, and of that class generally known as “ red 
short.” 
It may be as \vell here to mention that malleable 
iron is divided into two distinct classes, Red-short and 
cold-short; the former being generally produced from 
rich ores, and the latter from the poorer, or leaner ores. 
The pig iron made from the rich ores (under the cold 
blast process only) is not so fluid as that from the lean 
ores ; when, however, it has been converted into malle¬ 
able iron it is tough and fibrous when cold, but is 
t roublesome and difficult to be worked bv the smiths at 
less than a white heat; this want of ductility has caused 
it to be denominated “ rod short.” The pig iron pro¬ 
duced by the lean ores possesses, on the contrary, more 
fluidity, and is thence well adapted for small castings ; 
hut when it is manufactured into malleable iron, al¬ 
though in the hands of the smith it is ductile and easily 
worked, even at a dark red heat, it becomes when cold 
weak and unfitted to support sudden shocks, or con¬ 
tinued strains, and is hence called 41 cold short.” Good 
iron should appear fresh, somewhat reflex in its fibres, 
and silky. A dead colour indicates a weak iron, even 
though it is perfectly white. Dark but very lustrous 
iron is always superior to that which has a bright color 
and feeble lustre. Coarse fibres indicate a strong, but. 
if the iron is dark, an inferior article. Where the iron 
is of a white, bright colour, may indicate an article of 
superior quality for sheet iron and boiler plate, though 
soft for railroad iron. , 
The method hitherto adopted for the reduction of the 
ores of the Fitz Rov mines, has been, first, to crush it 
into small pieces, and with 25 per cent, of charcoal it is 
placed in a reverberatory furnace similar to that em¬ 
ployed in England for puddling, and the iron before 
you this evening is the produce of this mode of manu¬ 
facture. This plan hav been adopted (although pro¬ 
ducing but small quantities) owing to the slight cost of 
construction compared to the comparative great outlay 
required in the erection of a blast furnace with its 
necessary apparatus for blowing, &c.; and should the 
trials be satisfactory with the experimental furnace 
constructed (from a jdau I have given) at the Railway 
Station, it will be found that eight such furnaces of 
larger dimensions will be sufficient to produce the 
quantity of iron necessary for the present requirements 
of the company* But whether this is the best mode of 
proceeding is a question yet to be decided by future 
experiments. 
The fuel employed when manufacturing iron upon a 
large scale is coke. It is obvious, then, that without a 
good supply of fossil fuel the best iron mine must bo 
valueless. The spot where the coal is at present being 
worked is at a distance of one and a-balf miles from 
the iron, to which a good road has been constructed, 
but should the result of the borings be as is confidently 
expected* coal will then be obtained within a few yards 
of the works. The quality of the coal has been" thus 
described hv the Government examiner of coal fields, 
Mr. William Keene, whose opinion from his long ex¬ 
perience is entitled to more weight than mine can be. 
lie states that—“There is ample evidence of the ex¬ 
istence of a very Tegular deposit of ti ne coal; that is 
to say, it is not lignite—it is not a deposit of the ter¬ 
tiary epoch, or more recent than the sandstone, it be¬ 
longs, as does all that I have seen here, to the secondary 
true coal formation, is overlaid by regular beds of se¬ 
condary sandstone, lying in conformable strata ujhhi it 
of a thickness of twelve fathoms, and rc]>oses upon a 
true coal schist, which covers a second bed of coal of 
considerable thickness. The whole of the sandstone 
strata are laid bare down to the coal seam in a water- 
cut ravine, seventy feet deep from the top of the over¬ 
hanging rocks, which form the surface of a table-land, 
having a gentle inclination to the south.” 
“ One of the seams, four feet thick, is laid bare for a 
length of eighteen yards, the other below it is separated 
by a bed of fissile cl ay-si ate of rare regularity. The 
I top of the lower seam of coal forms the bed of the 
stream, and, from an examination of its course, I judged, 
the coal to be about equal in thickness to the upper 
I seam. _ In trials made of it, I found a free burning 
' bituminous or caking coal, fit for household or 
manufacturing purposes, and convertible into good 
coke.” 
The workings have hitherto been on the hill side, but 
owing to the seams having been distorted by the general 
disturbance of the strata and the obstructions made by 
the protruding dykes, it has been proved that the ulti¬ 
mate success of these mines (as predicted by Mr. 
Keene) mast depend upon its being found where it is 
now being sought for, namely, in the plains, and of the 
result attending the operations, I have little doubt, as 
already from the indication of the strata passed through 
they must be in close proximity to the coal. 
One of the last reports received on the boring opera¬ 
tions which are still going on, stated that in one place 
having sunk one hundred and fifty feet they entered a 
bed of shale which proved to lie three and a-half feet 
thick, upon passing through which they came upon a 
thin bed of “spongy iron ore” of only a few inches in 
depth, the tool bringing it up in small lumps. This 
was no sooner passed than the water which had hitherto 
stood in the bore hole at a level of fourteen feet from 
the surface of the ground suddenly fell to fifty-fonr 
