There are dozens of reaches upon the upper Thames where little is in sight save the willows, the meadows, and a village church tower, which present exactly the same aspect to-day as they did when that church was first built.  You might put a man of the fifteenth century on to the water below St. John’s Lock, and, until he came to Buscot Lock, he would hardly know that he had passed into a time other than his own.  The same steeple of Lechlade would stand as a permanent landmark beyond the fields, and, a long way off, the same church of Eaton Hastings, which he had known, would show above the trees.

There is another method of judging the comparative smallness of the change, and it is a method which can be applied to many other parts of England whose desertion or wildness in the Dark and early Middle Ages has been too confidently asserted.  That method is to note where human settlements were and are found.  With the exception of the long and probably marshy piece between Radcot and Shifford the whole of the upper Thames was dotted with such settlements, which, though small, were quite close to the banks.  Kelmscott is right up against the river in what one would otherwise have imagined to be land too marshy for building until modern times.  Buscot, on the other bank, is not only close to the river, but was a royal manor of high historical importance in the eleventh century.  Eaton Hastings is similarly placed right against the bank; so was in its day the palace of Kempsford above Lechlade, and so is the church of Inglesham between the two.  All the way down you have at intervals old stonework and old place names, indicating habitation upon the upper Thames.

A proper system of locks is comparatively modern on any European river.  The invention is even said (upon doubtful authority) to be as late as the sixteenth century, but the method of regulating the waters of a river by weirs is immemorial.

We have no earlier record of weirs upon the Thames than that in Magna Charta; but some such system must have existed from the time when men first used the Thames in a regular manner for commerce.

There is but one place left in which one can still reconstruct for oneself the aspect of such weirs as were till but little more than a century ago the universal method of canalising the river.  Modern weirs are merely adjuncts to locks, and are usually found upon a branch of the stream other than that which leads up to the lock.  But in this weir the old fashion of crossing the whole stream is still preserved.  There is no lock, and when a boat would pass up or down the paddles of the weir have to be lifted.  It is, in a modern journey upon the upper Thames, the one faint incident which the day affords, for if one is going down the stream but few paddles are lifted, and the boat shoots a small rapid, while to admit a boat going up stream the whole weir is raised, and, even so, a great rush of water opposes the boat as it is hauled through.  Some years ago there were several of these weirs upon the upper river.  They have all been superseded by locks, and it is probable that this last one will not long survive.