The ships of commerce haul up to the shore towards evening, and the crews, disembarking, light their fires and cook their food. There are, however, one or two gaps, as it were, in their usual course which they cannot pass in this leisurely manner; where the shore is exposed and rocky, or too shallow, and where they must reluctantly put forth, and sail from one horn of the land to the other.

The Lake is also divided into two unequal portions by the straits of White Horse, where vessels are often weather-bound, and cannot make way against the wind, which sets a current through the narrow channel. There is no tide; the sweet waters do not ebb and flow; but while I thus discourse, I have forgotten to state how they came to fill the middle of the country. Now, the philosopher Silvester, and those who seek after marvels, say that the passage of the dark body through space caused an immense volume of fresh water to fall in the shape of rain, and also that the growth of the forests distilled rain from the clouds. Let us leave these speculations to dreamers, and recount what is known to be.

For there is no tradition among the common people, who are extremely tenacious of such things, of any great rainfall, nor is there any mention of floods in the ancient manuscripts, nor is there any larger fall of rain now than was formerly the case. But the Lake itself tells us how it was formed, or as nearly as we shall ever know, and these facts were established by the expeditions lately sent out.

At the eastern extremity the Lake narrows, and finally is lost in the vast marshes which cover the site of the ancient London. Through these, no doubt, in the days of the old world there flowed the river Thames. By changes of the sea level and the sand that was brought up there must have grown great banks, which obstructed the stream. I have formerly mentioned the vast quantities of timber, the wreckage of towns and bridges which was carried down by the various rivers, and by none more so than by the Thames. These added to the accumulation, which increased the faster because the foundations of the ancient bridges held it like piles driven in for the purpose. And before this the river had become partially choked from the cloacæ of the ancient city which poured into it through enormous subterranean aqueducts and drains.

After a time all these shallows and banks became well matted together by the growth of weeds, of willows, and flags, while the tide, ebbing lower at each drawing back, left still more mud and sand. Now it is believed that when this had gone on for a time, the waters of the river, unable to find a channel, began to overflow up into the deserted streets, and especially to fill the underground passages and drains, of which the number and extent was beyond all the power of words to describe. These, by the force of the water, were burst up, and the houses fell in.

For this marvellous city, of which such legends are related, was after all only of brick, and when the ivy grew over and trees and shrubs sprang up, and, lastly, the waters underneath burst in, this huge metropolis was soon overthrown. At this day all those parts which were built upon low ground are marshes and swamps. Those houses that were upon high ground were, of course, like the other towns, ransacked of all they contained by the remnant that was left; the iron, too, was extracted. Trees growing up by them in time cracked the walls, and they fell in. Trees and bushes covered them; ivy and nettles concealed the crumbling masses of brick.

The same was the case with the lesser cities and towns whose sites are known in the woods. For though many of our present towns bear the ancient names, they do not stand upon the ancient sites, but are two or three, and sometimes ten miles distant. The founders carried with them the name of their original residence.

Thus the low-lying parts of the mighty city of London became swamps, and the higher grounds were clad with bushes. The very largest of the buildings fell in, and there was nothing visible but trees and hawthorns on the upper lands, and willows, flags, reeds, and rushes on the lower. These crumbling ruins still more choked the stream, and almost, if not quite, turned it back. If any water ooze past, it is not perceptible, and there is no channel through to the salt ocean. It is a vast stagnant swamp, which no man dare enter, since death would be his inevitable fate.

There exhales from this oozy mass so fatal a vapour that no animal can endure it. The black water bears a greenish-brown floating scum, which for ever bubbles up from the putrid mud of the bottom. When the wind collects the miasma, and, as it were, presses it together, it becomes visible as a low cloud which hangs over the place. The cloud does not advance beyond the limit of the marsh, seeming to stay there by some constant attraction; and well it is for us that it does not, since at such times when the vapour is thickest, the very wildfowl leave the reeds, and fly from the poison. There are no fishes, neither can eels exist in the mud, nor even newts. It is dead.

The flags and reeds are coated with slime and noisome to the touch; there is one place where even these do not grow, and where there is nothing but an oily liquid, green and rank. It is plain there are no fishes in the water, for herons do not go thither, nor the kingfishers, not one of which approaches the spot. They say the sun is sometimes hidden by the vapour when it is thickest, but I do not see how any can tell this, since they could not enter the cloud, as to breathe it when collected by the wind is immediately fatal.