o 1866 (_circa_), when the
construction of machinery by machinery became the settled rule of
industry.

Sec. 9. Bearing in mind how the invention of new specific forms of
machinery in the several processes of manufacture proceeds
simultaneously with the application of the new motor-power, we find
ourselves quite unable to measure the amount of industrial progress
due to each respectively. But seeing that the whole of modern industry
has thus been set upon a new foundation of coal and iron, it is
obvious that the bonds connecting such industries as the textile and
the iron must be continually growing closer and stronger. In earlier
times the interdependency of trades was slight and indirect, and the
progress in any given trade was almost wholly derived from
improvements in specific skill or in the application of specific
mechanical invention. The earlier eighteenth century did indeed
display an abnormal activity in these specific forms of invention. For
examples of these it is only necessary to allude to Lombe's silk mill
at Derby, the pin factory made famous by Adam Smith, Boulton's
hardware factory at Soho, and the renowned discoveries of Wedgwood.
But all increased productivity due to these specific improvements was
but slight compared with that which followed the discovery of steam as
a motor and the mechanical inventions rendering it generally
applicable, which marked the period 1790 to 1840. By this means the
several specific industries were drawn into closer unity, and found a
common basis or foundation in the arts of mining, iron-working, and
engineering which they lacked before.

From these considerations it will follow that the order in which the
several industries has fallen under the sway of modern industrial
methods will largely depend upon the facility they afford to the
application of steam-driven machinery. The following are some of the
principal characteristics of an industry which determine the order,
extent, and pace of its progress as a machine industry:--

(_a_) _Size and complexity of Structure._--The importance of the
several leading textile manufactures, the fact that some of them were
highly centralised and already falling under a factory system, the
control of wealthy and intelligent employers, were among the chief
causes which enabled the new machinery and the new motor to be more
quickly and successfully applied than in smaller, more scattered, and
less developed industries.

(_b_) _Fixi