pig-iron was double that of 1788, and the average
output per furnace raised to 1048 tons.

(4) The substitution of hot for cold blast in 1829, effecting an
economy of coal to the extent of 2 tons 18 cwt. per ton of cast-iron.

(5) The adoption of raw coal instead of coke in 1833, effecting a
further reduction of expenditure of coal from 5 tons 3-1/2 cwt. to 2
tons 5-1/4 cwt. in producing a ton of cast-iron.

These were the leading events in the establishment of the iron
industry of this country. The following table indicates the growth of
the production of English iron from 1740 to 1840:--

Year. No. of Furnaces. Average Output. Total Produce.
Tons. Tons.
1740 59 294 17,350
1788 77 909 coke } 61,300
545 charcoal}
1796 121 1048 125,079
1806 133 1546 258,206
1825 364 2228 703,184
(261 in blast)
1828 365 2530
(277 in blast)
1839 378 3592 1,347,790

Here we see that economy of power rather than improved machinery is
the efficient cause of the development of industry, or more properly,
that economy of power precedes and stimulates the several steps in
improvement of machinery.

The substitution of coke for charcoal and the application of steam
power not merely increased enormously the volume of the trade, but
materially affected its localisation. Sussex and Gloucester, two of
the chief iron-producing counties when timber was the source of power,
had shrunk into insignificance by 1796, when facilities of obtaining
coal were a chief determinant. By 1796, it is noteworthy that the four
districts of Stafford, Yorkshire, South Wales, and Salop were to the
front.

The discovery of the hot blast and substitution of raw coal for coke
occurring contemporaneously with the opening of railway enterprise
mark the new interdependence of industries in the age of machinery.

Iron has become a foundation upon which every machine-industry alike
is built. The metal manufactures, so small in the eighteenth century,
attained an unprecedented growth and a paramount importance in the
nineteenth.

The application of machinery to the metal industries has led to an
output of inventiv