1640, under the idea that the Danes threw up the hill--an idea for which there is not the slightest historical evidence.[325] We have seen that there is no reason to think that the Danes ever constructed fortifications of this kind, and their connection with this earthwork is due to one of those guesses, too common in English archæology, which have no scientific basis whatever. Somner makes the important statement that this earthwork was originally outside the city walls. His words are:-- "I am persuaded (and so may easily, I think, anyone be that well observes the place) that the works both within and without the present wall of the city were not counterworks one against the other, as the vulgar opinion goes, but were sometimes all one entire plot containing about 3 acres of ground, of a triangular form (the outwork) with a mount or hill entrenched round within it; and that when first made or cast up it lay wholly without the city wall; and hath been (the hill or mount, and most part also of the outwork), for the city's more security, taken in and walled since; that side of the trench encompassing the mound now lying without and under the wall fitly meeting with the rest of the city ditch, after either side of the earthwork was cut through to make way for it, at the time of the city's inditching."[326] It is not often we are so fortunate as to have so clear a description of an earthwork which has almost entirely disappeared; but the description is confirmed by Stukeley and Hasted, and down to the making of the Chatham and Dover railway in 1860 the earthworks of the part of the bailey which was left outside the city wall were still to be seen, and were noticed by Mr G. T. Clark.[327] It is clear that Somner's description corresponds exactly, even in the detail of size, to the type of a motte-and-bailey castle.