The peat gradually displaced an early forest of giant oaks. Their stems are still there, standing rooted in the older clay. Where they once stood no trees now grow. The whole face of the land has changed. Some great change of climate must lie behind this vanishing of vast forests, this gradual growth of peat-covered moors. A dry climate must have changed to one much damper; heat must have changed to cold, warm winds to chilly storms. In the southern promontories, among red sandstone hills, still linger survivors of that more genial clime--groves of arbutus that speak of Greece or Sicily; ferns, as at Killarney, found elsewhere only in the south, in Portugal, or the Canary Islands.
On the southwestern horizon from Toppid Mountain, when the sky is clear after rain, you can trace the outline of the Curlew hills, our southern limit of view from Knocknarea. Up to the foot of the hills spreads a level country of pastures dappled with lakes, broken into a thousand fantastic inlets by the wasting of the limestone rock. The daisies are the stars in that green sky. Just beyond the young stream of the Shannon, where it links Lough Garra to Lough Key, there is a lonely cromlech, whose tremendous crown was once upheld by five massive pillars. There is a kindred wildness and mystery in the cromlech and the lonely hills.
Southward again of this, where the town of Lough Rea takes its name from the Gray Lake, stands a high hill crowned by a cromlech, with an encircling earthwork. It marks a green ring of sacred ground alone upon the hill-top, shut off from all the world, and with the mysterious monument of piled stones in its centre; here, as always, one huge block upheld in the air by only lesser blocks. The Gray Lake itself, under this strange sentry on the hill, was in long-passed ages a little Venice; houses built on piles lined its shores, set far enough out into the lake for safety, ever ready to ward off attack from the land. This miniature Venice of Lough Rea is the type of a whole epoch of turbulent tribal war, when homes were everywhere clustered within the defence of the waters, with stores laid up to last the rigors of a siege.
The contrast between the insecurity and peril of the old lake dwellings and the present safety of the town, open on all sides, unguarded and free from fear, is very marked. But not less complete is the contrast between the ancient hamlet, thus hidden for security amid the waters, and the great cromlech, looming black against the sky on the hill's summit, exposed to the wildness of the winds, utterly unguarded, yet resting there in lonely serenity.
A little farther south, Lough Gur lies like a white mirror among the rolling pasture-lands of Limerick, set amongst low hills. On the lake's shore is another metropolis of the dead, worthy to compare with Carrowmore on the Sligo headland. Some of the circles here are not formed of single stones set at some distance from each other, but of a continuous wall of great blocks crowded edge to edge. They are like round temples open to the sky, and within one of these unbroken rings is a lesser ring like an inner shrine. All round the lake there are like memorials--if we can call memorials these mighty groups of stone, which only remind us how much we have forgotten. There are huge circles of blocks either set close together or with an equal space dividing boulder from boulder; some of the giant circles are grouped together in twos and threes, others are isolated; one has its centre marked by a single enormous block, while another like block stands farther off in lonely vastness. Here also stands a chambered cromlech of four huge flat blocks roofed over like the cromlech under Slieve Callan across the Shannon mouth.
The southern horizon from Lough Gur is broken by the hills of red sandstone rising around Glanworth. Beside the stream, a tributary of the Blackwater, a huge red cromlech rises over the greenness of the meadows like a belated mammoth in its uncouth might. To the southwest, under the red hills that guard Killarney on the south, the Sullane River flows towards the Lee. On its bank is another cromlech of red sandstone blocks, twin-brother to the Glanworth pile. Beyond it the road passes towards the sunset through mountain-shadowed glens, coming out at last where Kenmare River opens into a splendid fiord towards the Atlantic Ocean. At Kenmare, in a vale of perfect beauty green with groves of arbutus and fringed with thickets of fuchsia, stands a great stone circle, the last we shall record to the south. Like all the rest, it speaks of tremendous power, of unworldly and mysterious ends.
The very antiquity of these huge stone circles suggests an affinity with the revolving years. And here, perhaps, we may find a clue to their building. They may have been destined to record great Time itself, great Time that circles forever through the circling years. There is first the year to be recorded, with its revolving days; white winter gleaming into spring; summer reddening and fading to autumn. Returning winter tells that the year has gone full circle; the sun among the stars gives the definite measure of the days. A ring of thirty-six great boulders, set ten paces apart, would give the measure of the year in days; and of circles like this there are more than one.
In this endless ring of days the moon is the measurer, marking the hours and weeks upon the blue belt of night studded with golden stars. Moving stealthily among the stars, the moon presently changes her place by a distance equal to her own breadth; we call the time this takes an hour. From her rising to her setting, she gains her own breadth twelve times; therefore, the night and the day are divided each into twelve hours. Meanwhile she grows from crescent to full disk, to wane again to a sickle of light, and presently to lose herself in darkness at new moon. From full moon to full moon, or from one new moon to another, the nearest even measure is thirty days; a circle of thirty stones would record this, as the larger circle of thirty-six recorded the solar year. In three years there are thrice twelve full moons, with one added; a ring of thirty-seven stones representing this would show the simplest relation between sun and moon.