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