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iron. The pig metal is usually the excess of the tap that the refinery will not 
contain, and is generally used for castings. The more gray the color of the re¬ 
fined iron, the better is its quality. The cinders, both of the refinery and the forge 
are remelted—-the latter being of a better quality but not so rich as the former—the 
one yielding about 40 and the other about 60 per cent. 
There is here a very ingenious mode, which I have also seen elsewhere, to ele¬ 
vate or lower the materials which may be required for different parts of the works. 
It is by means of a water tank, which wastes its water in a certain ratio, so as 
to produce a nearly uniform velocity in its vertical movement. 
The Dowlas works consist of 20 large furnaces, numerous forges and rolling 
mills, and gives occupation to about 5,000 persons, with an average expenditure 
of near £40,000 per month. The nett profits are variously estimated to range 
between £100,000 and more than £200,000 per annum. 
An excellent kind of fire-brick is made here, and I am told that some of the fur¬ 
naces have been kept in constant blast for 25 years, without the hearths having 
been burnt out. You can imagine nothing more imposing than this view at night, 
with the whole valley in one broad glare of light from the furnaces and forges, 
and filled with the clash and din of the ponderous trip-hammers. 
December 11.—Left this morning at 7 o’clock, for Pontypool, by the way of 
Tredegar. Called at the works of Thomson, Humfry, & Co. There are here 
seven blast furnaces in operation. Besides the local ores, they use the Cornish, 
Devon, and Lancashire. The very best are from the Haytor mines from Corn¬ 
wall, both in yield and quality. It gives about 60 per cent. The next is from Lan¬ 
cashire, the botryoidal brown hematite. Much of the Cornish ore is a species 
of red ochre in a pulverised state; and the Devonshire a kind of red hematite. 
Mr. Humfry, the very intelligent agent and co-proprietor of these works, informs me 
that the native ores, or ores of the coal measures, are quite equal in richness and 
quality to most of the coast-borne ores. They are compelled to coke all the coal 
consumed here, as it contains too much bitumen to burn freely in blast furnaces. 
For ordinary purposes it is not much coked, losing about one-fourth of its weight; 
but when intended for the refinery, it loses about one-third. They do not here 
draw out the crude metal in the refinery from the tap, as at Dowlas, but run it 
into pigs, which are broken and then re-melted in a refinery v\ ith coke, and 
again drawn off. I here noticed a very ingenious method of preserving the nozzles 
of the blast pipes from burning, three of which terminate in each refinery. It is 
by passing a constant stream of cold water through the annular part of the pipe, 
which runs out warm but not hot. Without this contrivance the nozzles would 
soon be consumed. From the refinery the iron is carried through the usual pro¬ 
cesses of puddling, rolling, &c, &c.. according to the uses for which it is design¬ 
ed. Saw it drawn out into long red ribbons for hoops, Then went to see rail¬ 
way iron rolled ; very similar to that described at Dowlas. At these works many 
rails have been manufactured for America. They were rolling iron while I was 
present for the “ Athens Branch Railroad,” Georgia; weight 17^ lbs. per yard— 
broad at bottom and narrow at top, to be fastened down by spikes through the 
