There is, however, more to consider. Why should Cnut make a semicircle when an arc would serve his turn? All he had to do was to draw an arc of a circle with the radius just found, to clear any obstacles in the way of approach to the Bridge, and use that arc for his canal. This is most certainly what he did: I am quite certain he adopted this method, because it was the only sensible thing to do. He would thus get off with a canal about fifty yards long, of which the only difficulty would be the cutting through the Embankment and the Causeway. What would be the depth of the canal? Look at this section of the Gokstad ship. With her breadth of sixteen feet, she had only four feet in depth; without her company and crew, and their arms and provisions, she would thus draw no more than a few inches--certainly not more than eight inches or so. Freeman's deep canal therefore comes to eight inches at the most. But there is still another consideration which lessened the labour materially. The ground behind the Embankment was a little lower than the river at high tide: the Danes, therefore, had only to construct a low wooden containing-wall of timber on each side in order to make their canal without excavating an inch. When that was done, the cutting of the Embankment let in the tide and did the rest. In this simple manner do we reduce Cnut's colossal work of a deep canal, four miles and a half long, into a piece of construction and demolition which would take a large body of men no more than a few hours. If, however, there actually was any digging to be done, we must remember that the ground was a level; that there were no stones or rocks in the way, and that it consisted of a soft black _humus_, the result of ages of successive growths of sedge and coarse grass, formerly washed twice a day by the brackish waters of a tidal river. The object of the canal once attained, the ships drawn back again, Cnut, of course, left the place to be repaired by any who pleased. The broken Embankment let in the tide; the broken Causeway cut off any approach to the river; but Southwark was deserted. When things settled down a little, workmen were sent across from London, and the broken places were repaired. Then all traces of the canal disappeared. Thirty-six years later, in 1052, Earl Godwine arrived at Southwark with a fleet and an army. He had no difficulty in passing the Bridge; he waited till flood-tide, and then sailed through 'on the south side.' It is quite impossible to explain this statement, or to make it agree with the difficulty felt by Cnut. The Bridge may have sustained some damage; there may have been a drawbridge; or Godwine's ships may have been smaller: one knows nothing. I merely state the fact as the Chronicler gives it. One more glimpse of the Bridge from Southwark before we pass on to more modern times. [Illustration: Ships of William the Conqueror]