I could add, were I not afraid of confusing the reader, many other examples of this necessity. For instance, when one runs from the Belgian ports, or Dunkirk, to England, ever so little a change in the wind may make it necessary to go north above the North Foreland. Again, there is the barrier of the Goodwins, which, in spite of legend, is probably prehistoric. If you could not get well south of that barrier at the first trial you had to go north of it. Everything has compelled men, so far, to provide as many chances as possible upon this coast, and at the present day the breakwater at Folkestone, the desperate attempt which many still make to use the harbour of Rye, to some extent the great works of Dover, the poor relic of Sandwich, the continual improvement of Ramsgate, point to the same necessity. Perhaps some refuge less distant from the sea than the estuary of the Swale will be made again to replace Reculvers upon the north of the Kentish coast. [Illustration] Now it is this multiplicity of Kentish harbours proceeding from the conditions of the tide which has created Canterbury. When an army has to spread out like the fingers of a hand or the sticks of a fan in order to cover a wide area, it must start from some point of concentration. When commerce is in doubt as to whether it will use this, that, or another out of many gates, it must equally have this point of concentration. When defenders are expecting an invasion from many points of a circumference, their only plan is to make their base some central point whence radii depart to that circumference. When the traveller is uncertain which of six places he can choose for his departure, he will halt at some point more or less central, while his decision is being made for him by the weather or by other circumstances. When a merchant, landing, knows not in which of six towns he shall land, he must at least be certain that some one town, common as it were to all the six, can be reached the day after his landing; he must know that his correspondents can meet him there, and that he may make that common town his depôt for further transactions inland. Thus it was that the six Kentish ports and more, standing on the edge of that rounded county, created Canterbury inland. * * * * * The town might have stood, theoretically, at any one of a great number of points; geometrically perhaps it ought to have been near the village of Goodnestone, which is the centre of all this circumference from Reculvers round to Lympne. But there is one governing condition which forbids us to look for such a centre anywhere save upon one line, and that condition is the river Stour. It is the only considerable body of fresh water, and the only easy means of communication with the interior. On the Stour, then, would the centre of these ports be.