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.