The reason of this arrangement was as follows: an inland place has many advantages over a fortified town on the seashore as the resting-place of an army. It has a better food supply; communication from it radiates upon all sides, not only from half its circumference (indeed in many ports there is but one narrow exit along the isthmus of the peninsula or up the valley which forms its harbour). There is likely to be more wood, a matter of great importance for fuel and fortification and sometimes for the construction of engines of war; it will have more fresh water. It may not be a salient, but it is an important, fact that in early times the population of an inland place would be trained for fighting upon land, and its energies would not be divided by the occupation of sea-faring; and finally, your inland fortress is liable to but one form of attack. You may have landed your men after a successful voyage, but, on the other hand, you may have landed them after a hot pursuit. In the first case it is not a disadvantage to sleep the night sheltered by walls inland, and in the second case it is a necessity. Remembering all these things, it is evident that to have your town of refuge within a day's march of the landing-place is a condition of its value to you. It is far preferable to reach fortification within the daylight than to pass your first halt under the strain of partial and temporary defence. Winchester and Canterbury are each, of course, upon rivers. They are each upon rivers just above the limit to which the tide would help light-draught, primitive boats, and where yet they could enjoy the fresh water coming down from above. So Caen, so Norwich, and a hundred other cities, have been founded upon rivers a day's march inland from port, and (with the exception of the tide) similar conditions perhaps produced the greatest of all these examples--Rome. The similarity of the rivers is also remarkable: each of such a size that it can be canalised for traffic above the city, and yet used to turn mills; each supplying industries that depend upon water, especially brewing and tanning; each divided for such a purpose into a number of small regular trenches which flow along the lower streets of the city--an arrangement only possible where a flat site has been chosen--the Itchen, tumbling along the eastern boundary of Winchester, and the Stour, on the northern gate of Canterbury, complete a parallel almost as strong as that of the cities which stand upon them. They are of much the same length, depth, rapidity of stream, and volume of water. They flow very clear--running over the chalk, clean and potable streams. At a point where each cuts through a range of hills, a point somewhat below the last ancient ford, and just barely above the recorded limit of the tide, a point right on the valley floor where the hills recede somewhat, each bears its city.