"The people of the river are suspended in the river's time, which has some deep affinity with a world that existed before the concept of time itself. Perhaps we will come to describe it as timeless. It runs in an eternal present that, according to philosophers, is the one part of time that does not really exists. But if it were to be stilled, it would lose its identity.
Yet, curiously enough, water has also been employed as a measurement of human time. The water clock or clepsydra was in use many thousands of years ago, and the first of these devices was a simple jar with a hole drilled through its bottom. But the Thames itself makes some claim to being 'the place where time begins' since on its banks, at Greenwich, is the site of the prime meridian. A large red 'time ball', constructed in 1833, rises up a pole on the turret of the Observatory and falls at precisely 1.00pm as the signal of Greenwich Mean Time. The great clocks of London are by the river. Big Ben was preceded, at Westminster, by a 'tall pointed tower' in Old Palace Yard by the Thames; this was, according to Stow, 'a tower of stone containing a clock which striketh at every hour on a great bell...the same clock, in a calm, will be heard into the city of London'. There is a great clock on Shell Mex House. So the eternal river enters the human world.
The flow of the Thames has inspired another form of measurement. The Bridgetime convent at Syon and the Charterhouse at Sheen faced each other on opposite banks, and Henry VI declared that 'immediately upon the cessation of the service at one convent it should commence at the other, and so should continue until the end of time'.
These perpetually flowing orisons are a spiritual image of the water running between them. the Thames can become an emblem both of time and of eternity, the Janus-faced aspects of the river like the sculptured heads on Henley Bridge looking both upriver and downriver. In his book, The Stripling Thames (1909), Fred Thacker pronounced thus:
Ancient river, changing never,
Symbol of eternity,
Gliding water, lapsing ever,
Mirror of inconstancy."
From 'Thames - Sacred River' by Peter Ackroyd
