The particulars of these various earthworks, so different in plan and extending over so many centuries, deserve a separate notice, and therefore, though originally intended to have been here treated of, it seemed more prudent to lay this branch of the subject aside for the present, in the hope that it may be taken up when the completion of the larger scale Ordnance Maps shall afford more accurate and copious data than now can conveniently be procured. The subject, in fact, should have entered into the instructions given to the officers of the Survey, by which means we should at least have avoided the obscure and sometimes contradictory system of nomenclature by which these works have been designated at different periods of this great, and in most respects admirable, national undertaking. But, although it be expedient here to pass by in silence those earthworks, irregular, rectangular, or concentric, which have no direct connexion with the subsequent castles of masonry, and therefore with military architecture, there remain, nevertheless, certain earthworks which are so connected, and which must therefore here be noticed, and are of importance sufficient to require a separate chapter for their consideration. CHAPTER II. EARTHWORKS OF THE POST-ROMAN AND ENGLISH PERIODS. But little is recorded of the internal condition of Britain between the departure of the Legions, A.D. 411, and the arrival of the Northmen in force thirty or forty years later; but whatever may have been the effect of Roman dominion, or of the infusion of Roman blood, upon the social or commercial character of the Britons, it is at least certain that they had made little progress in the construction of places of defence. The Romans dealt rather with the country than with the people. The foreign trade under the Roman sway was no doubt considerable, and much land was under cultivation, but the Britons seem to have acquired but few of the Roman arts, and nothing of the Roman discipline. Neither have their descendants, the Welsh, many customs which can be traced distinctly to a Roman origin; and although there are many words in their language which show its origin to be cognate with the Latin, there are comparatively few which can, with any probability, be shown to be derived from the Latin. How far against the Scots and Picts they made use of Roman tactics or employed Roman weapons is but little known. In defending themselves against the Northmen they, no doubt, took advantage of the Roman walls at Richborough and Lymne, and afterwards of Pevensey, but on the whole with only temporary success; and from these they were driven back upon the earthworks of their probably remote predecessors. There is not a shadow of evidence that they constructed any new defensive works in masonry upon the Roman models, or even repaired those that were left to them in the same material.