_Martello Towers._--One of the last types of masonry fortifications to be erected, as distinguished from structures which are known as forts and redoubts, was also in idea one of the most ancient. Martello Towers, of which so many were built on the coast of Essex, Kent, and Sussex, were based on the model of a tower on Cape Martello, on the Gulf of San Fiorenzo, in Corsica. They are built of solid masonry, but contain vaulted rooms for the garrisons. They are furnished with a flat platform on top for two or three guns, and access to them is by means of a ladder leading to a side doorway, about twenty feet above the level of the ground. In some cases a deep ditch was cut round the towers. Many of these coast defences were erected on the south-eastern shores of England as a protection against the expected naval invasion under Napoleon I. The whole coast in the neighbourhood of Folkestone, Sandgate, and Hythe, and at other points, was defended in this way by Martello Towers, forts, and earthworks, with a view of resisting Napoleon's invasion. At the same period a great military canal was constructed from Hythe, extending inland to Appledore, and then on to Rye in Sussex. PART V MISCELLANEOUS DEFENCES THE NAVY THE CINQUE PORTS DEFENSIVE CHAINS, ETC. THE COASTGUARD THE NAVY The scope of the present volume is to review the defensive works which have been carried out in various ages for the protection of our shores against incursions of enemies: the story of our naval exploits does not primarily come within it. The first duty of our English navy is, and always has been, offensive, as well as defensive. In times of peace we have been accustomed to regard our Navy as our first line of defence, and this is a perfectly accurate description of its functions. But it is obvious that these functions have always been different from, and in most periods independent of, what is generally understood by the term coast defences. Yet, again and again, the coast fortresses have assisted the operations of our war-ships when resisting the enemy, and to a certain extent the two forces have always been, and possibly always will be closely connected. Reference to the story of the Roman fleet for the defence of the shore of Britain, and also to the English navy under King Alfred, has already been made, but the beginning of the English navy may be traced to a somewhat later period. It had its origin in the Cinque Ports. THE CINQUE PORTS