t was wanted. A
second genius, to the horror of his fellow-tribesmen--who declared that
this time the world really would come to an end--shifted the pine a few
feet so as to bring it across the stream and into the place where it was
wanted. This man was the inventor of bridges--his family repudiated him,
and he came to a bad end. From this to cutting down the pine and
bringing it from some distance is an easy step. To avoid detail, let us
come to the old Roman horse-road over the Alps. The time between the
shepherd's path and the Roman road is probably short in comparison with
that between the mere chamois track and the first thing that can be
called a path of men. From the Roman we go on to the mediaeval road with
more frequent stone bridges, and from the mediaeval to the Napoleonic
carriage-road.

The close of the last century and the first quarter of this present one
was the great era for the making of carriage-roads. Fifty years have
hardly passed, and here we are already in the age of tunnelling and
railroads. The first period, from the chamois track to the foot road,
was one of millions of years; the second, from the first foot road to the
Roman military way, was one of many thousands; the third, from the Roman
to the mediaeval, was perhaps a thousand; from the mediaeval to the
Napoleonic, five hundred; from the Napoleonic to the railroad, fifty.
What will come next we know not, but it should come within twenty years,
and will probably have something to do with electricity.

It follows by an easy process of reasoning that after another couple of
hundred years or so, great sweeping changes should be made several times
in an hour, or indeed in a second, or fraction of a second, till they
pass unnoticed as the revolutions we undergo in the embryonic stages, or
are felt simply as vibrations. This would undoubtedly be the case but
for the existence of a friction which interferes between theory and
practice. This friction is caused partly by the disturbance of vested
interests which every invention involves, and which will be found
intolerable when men become millionaires and paupers alternately once a
fortnight--living one week in a palace and the next in a workhouse, and
having perpetually to be sold up, and then to buy a new house and
refurnish, &c.--so that artificial means for stopping inventions will be
adopted; and partly by the fact that though all inventions breed in
geometrical ratio, yet some multi