The common people aver that demons reside in these swamps; and, indeed, at night fiery shapes are seen, which, to the ignorant, are sufficient confirmation of such tales. The vapour, where it is most dense, takes fire, like the blue flame of spirits, and these flaming clouds float to and fro, and yet do not burn the reeds. The superstitious trace in them the forms of demons and winged fiery serpents, and say that white spectres haunt the margin of the marsh after dusk. In a lesser degree, the same thing has taken place with other ancient cities. It is true that there are not always swamps, but the sites are uninhabitable because of the emanations from the ruins. Therefore they are avoided. Even the spot where a single house has been known to have existed, is avoided by the hunters in the woods.
They say when they are stricken with ague or fever, that they must have unwittingly slept on the site of an ancient habitation. Nor can the ground be cultivated near the ancient towns, because it causes fever; and thus it is that, as I have already stated, the present places of the same name are often miles distant from the former locality. No sooner does the plough or the spade turn up an ancient site than those who work there are attacked with illness. And thus the cities of the old world, and their houses and habitations, are deserted and lost in the forest. If the hunters, about to pitch their camp for the night, should stumble on so much as a crumbling brick or a fragment of hewn stone, they at once remove at least a bow-shot away.
The eastward flow of the Thames being at first checked, and finally almost or quite stopped by the formation of these banks, the water turned backwards as it were, and began to cover hitherto dry land. And this, with the other lesser rivers and brooks that no longer had any ultimate outlet, accounts for the Lake, so far as this side of the country is concerned.
At the western extremity the waters also contract between the steep cliffs called the Red Rocks, near to which once existed the city of Bristol. Now the Welsh say, and the tradition of those who dwell in that part of the country bears them out, that in the time of the old world the River Severn flowed past the same spot, but not between these cliffs. The great river Severn coming down from the north, with England on one bank and Wales upon the other, entered the sea, widening out as it did so. Just before it reached the sea, another lesser river, called the Avon, the upper part of which is still there, joined it passing through this cleft in the rocks.
But when the days of the old world ended in the twilight of the ancients, as the salt ocean fell back and its level became lower, vast sandbanks were disclosed, which presently extended across the most part of the Severn river. Others, indeed, think that the salt ocean did not sink, but that the land instead was lifted higher. Then they say that the waves threw up an immense quantity of shingle and sand, and that thus these banks were formed. All that we know with certainty, however, is, that across the estuary of the Severn there rose a broad barrier of beach, which grew wider with the years, and still increases westwards. It is as if the ocean churned up its floor and cast it forth upon the strand.
Now when the Severn was thus stayed yet more effectually than the Thames, in the first place it also flowed backwards as it were, till its overflow mingled with the reflux of the Thames. Thus the inland sea of fresh water was formed; though Silvester hints (what is most improbable) that the level of the land sank and formed a basin. After a time, when the waters had risen high enough, since all water must have an outlet somewhere, the Lake, passing over the green country behind the Red Rocks, came pouring through the channel of the Avon.
Then, farther down, it rose over the banks which were lowest there, and thus found its way over a dam into the sea. Now when the tide of the ocean is at its ebb, the waters of the Lake rush over these banks with so furious a current that no vessel can either go down or come up. If they attempted to go down, they would be swamped by the meeting of the waves; if they attempted to come up, the strongest gale that blows could not force them against the stream. As the tide gradually returns, however, the level of the ocean rises to the level of the Lake, the outward flow of water ceases, and there is even a partial inward flow of the tide which, at its highest, reaches to the Red Rocks. At this state of the tide, which happens twice in a day and night, vessels can enter or go forth.
The Irish ships, of which I have spoken, thus come into the Lake, waiting outside the bar till the tide lifts them over. The Irish ships, being built to traverse the ocean from their country, are large and stout and well manned, carrying from thirty to fifty men. The Welsh ships, which come down from that inlet of the Lake which follows the ancient course of the Severn, are much smaller and lighter, as not being required to withstand the heavy seas. They carry but fifteen or twenty men each, but then they are more numerous. The Irish ships, on account of their size and
