ength
hit upon some contrivance that will get over the definite difficulty
and secure the particular economy. If we take any definite invention
and closely investigate it, we shall find in nearly every case it has
thus grown by small increments towards feasibility. Scientific men,
strictly so-called, have had very little to do with these great
discoveries. Among the great textile inventors, Cartwright alone was a
man leading a life of thought.[75] When the spinning machinery was
crippled in its efficiency by the crude methods of carding, Lees and
Arkwright set themselves to apply improvements suggested by
common-sense and experience; when Cartwright's power-loom had been
successfully applied to wool, Horrocks and his friends thought out
precisely those improvements which would render it remunerative in the
cotton trade.

Thus in a given trade where there are several important processes, an
improvement in one process which places it in front of the others
stimulates invention in the latter, and each in its turn draws such
inventive intelligence as is required to bring it into line with the
most highly-developed process. Since the later inventions, with new
knowledge and new power behind them, often overshoot the earlier ones,
we have a certain law of oscillation in the several processes which
maintains progress by means of the stimulus constantly applied by the
most advanced process which "makes the pace." There is nothing
mysterious in this. If one process remains behind in development each
increment of inventive effort successfully applied there brings a
higher remuneration than if applied to any of the more forward
processes. So the movement is amenable to the ordinary law of "Supply
and Demand" enforced by the usual economic motives. As the invention
of the fly-shuttle gave weaving the advantage, more and more attention
was concentrated upon the spinning processes and the jenny was
evolved; the deficiency of the jenny in spinning warp evolved the
water-frame, which for the first time liberated the cotton industry
from dependence upon linen warp: the demand for finer and more uniform
yarns stimulated the invention of the mule. These notable improvements
in spinning machinery, with their minor appendages, placed spinning
ahead of weaving, and stimulated the series of inventions embodied in
the power-loom. The power-loom was found to be of comparatively little
service until the earlier processes of dressing and sizing