The Thames
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 re- construct 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 super- seded by locks, and it is probable that this last one will not long survive.
Such weirs did certainly sufficiently regulate the stream as to make its banks regularly habitable. If no local order,
31
