stone circle, which the first growth of peat found already there, must
be at least as old, and may be indefinitely older. By careful count it
is found that one foot of black peat is made up of eight hundred layers;
eight hundred summers and eight hundred winters went to the building of
it. One foot of black peat, therefore, will measure the time from before
the founding of Rome or the First Olympiad to the beginning of our era.
Another foot will bring us to the crowning of Charlemagne. Yet another,
to the death of Shakespeare and Cervantes. Since then, only a few inches
have been added. Here is a chronometer worthy of our great cromlechs and
stone circles.

Some of these, as we saw, rest on the clay, with a sea of peat twelve
feet deep around and above them. Every foot of the peat stands for eight
centuries. Since the peat began to form, eight or ten thousand years
have passed, and when that vast period began, the great monuments of
stone were already there. How long they had stood in their silence
before our chronometer began to run we cannot even guess.

At Cavancarragh, on the shoulder of Toppid Mountain, some four miles
from Enniskillen, there is one of these circles; a ring of huge stone
boulders with equal spaces between stone and stone. A four-fold avenue
of great blocks stretches away from it along the shoulder of the hill,
ending quite abruptly at the edge of a ravine, the steep channel of a
torrent. It looks as if the river, gradually undermining the hillside,
had cut the avenue in halves, so that the ravine seems later in date
than the stones. But that we cannot be quite sure of. This, however, we
do certainly know: that since the avenue of boulders and the circle of
huge red stones were ranged in order, a covering of peat in some parts
twelve feet thick has grown around and above them, hiding them at last
altogether from the day. In places the peat has been cut away again,