Children are still taken to test out the great iron knocker hanging on a door at one end of the north side of the cloisters in Neville’s Court. If you stamp hard on a flagstone near the library entrance, the sound of the nocker knocking can be heard. Children and seemingly also adults have been trying this for years. The Revd Edward Conybeare write in 1910, ‘So great a part does illusion play in human impressions, that five people out of six, when they hear this sound, are ready to declare that they have seen the knocker actually move.’ Enid Porter, writing in 1969, recalled as a child being convinced she saw this.
It is a peculiar stone that had to be stamped on to make the knocker knock, one with a heel-shaped depression perhaps caused by weathering. The stamping also had to be done with one’s back to the knocker – part of the magic was to whisk around quickly to see it rise and fall. A faint hope this: the sound is the echo for which the cloister is famous. According to the Revd My Conybeare, ‘It was by timing this echo…that Sir Isaac Newton first measured the velocity of sound.’
The tradition is part of a broader one used to beguile children: that – if only you can catch them at it – certain standing stones and statues move on their own accord.