The Thames
the reason that its use as a limit is more apparent in civilised than in uncivilised times, is simply the fact that limits and boundaries themselves are never of great exactitude save in times of comparatively high civilisation. It is when a complex system of law and a far-reaching power of execution are present in a country that the necessity for precise delimitation arises. In the barbaric period of England there was no such necessity. Doubtless the men of Berkshire and the men of Oxfordshire felt themselves to be in general divided by the stream; but had we documents to hand (which, of course, we have not) it might be possible to show that exceptional tracts, such as the isolated Hill of Witham (which is much more influenced by Oxford than by Abingdon), was treated as the land of Oxfordshire men in early times, or was perhaps a territory in dispute; and something of the same sort may have existed in the connection of Caversham with Reading.
In this old age of our civilisation the exactitude of the boundary which the Thames establishes is apparent in various survivals. Islands now joined to the one bank and indistinguishable from the rest of the shore are still annexed to the farther shore. Such a patch is to be found at Streatley, geographically in Berkshire, legally in Oxford; there is another opposite Staines, which Middlesex claims from Surrey. In all, half-a-dozen or more such anomalous frontiers mark
