The steam engine familiarly explained and illustrated; with an historical sketch of its invention and progressive improvement; its applications to navigation and railways; with plain maxims for railway speculators. By the Rev. Dionysius Lardner ... With additions and notes by James Renwick ...

LOCOMOTIVE ENGINES ON RAILWAYS. 207
and the most precious qualities of each are never imparted
to the other. Like solids in physics, they are slow to form
combinations; but when the quality of fluidity has been imparted to them, when their constituent atoms are loosened
by fusion, and the particles of each flow freely through and
among those of the other, then the affinities are awakened,
new combinations are formed, a mutual interchange of qualities takes place, and compounds of value far exceeding those
of the original elements are produced. Extreme facility of
intercourse is the fluidity and fusion of the social masses,
from whence such an activity of the affinities results, and
from whence such an inestimable interchange of precious
qualities must follow. We have, accordingly, observed, that
the advancement in civilization and the promotion of intercourse between distant masses of people have ever gone on
with contemporaneous progress, each appearing occasionally
to be the cause or the consequence of the other. Hence it
is that the urban population is ever in advance of the rural
in its intellectual character. But, without sacrificing the
peculiar advantages of either, the benefits of intercourse may
be extended to both, by the extraordinary facilities which
must be the consequence of the locomotive projects now in
progress. By the great line of railroad which is in progres
from London to Birmingham, the time and expense of
passing between these places will probably be halved, and
the quantity of intercourse at least quadrupled, if we consider only the direct transit between the terminal points of
the line; but if the innumerable tributary streams which will
flow from every adjacent point be considered, we have no
analogies on which to build a calculation of the enormous
increase of intercommunication which must ensue.
Perishable vegetable productions necessary for the wants
of towns must at present be raised in their immediate
suburbs; these, however, where they can be transported.
with a perfectly smooth motion at the rate of twenty miles
an hour, will be supplied by the agricultural labourer of