SIR – I am giving a lecture on Friday at the Cider Museum in Hereford, under the auspices of the Hay-on-Wye Festival, about Thomas Andrew Knight, who was the second president of the Royal Horticultural Society from 1811 to 1838.

The Worcester connection is that John Williams (1773-1853), of Pitmaston House, was a close friend of Knight and, for instance, came to Worcester in 1836 for the annual meeting of the Worcestershire Natural History Society at the Guildhall.

My research interest has been on both Knight and Williams for a long time and this now continues as an honorary research fellow of the University of Worcester.

DR MURRAY MYLECHREEST, Worcester