THIS is the last of Mr. Valentine's talks on holidays in Britain, and in it he will describe one of the most beautiful parts of the country-the region between the Severn and the Usk, where England and Wales 'meet; where the lovely scenery of the Wye Valley competes in interest with the historic buildings, such as Tintern Abbey, Hereford Cathedral, and Ludlow Castle, in which this country is so rich.