To the Londoner the thought of Hyde Park conjures up a succession of colourful scenes : the Row with its riders of all ages and degrees of skill ; the sun gleaming on the Serpentine, its surface ruffled by ducks, Lido bathers, and rowing-boats ; the drone of traffic ; nursemaids and children and barking dogs and down-and-outs ; music from the bandstand punctuated by the ' ping ' of ticket-collectors' punches. Clough Williams-Ellis , a well-known architect, will give his impressions of these scenes, and lively impressions they are, too. He will talk about everything that has to do with the Park, from the historical seizure of the grounds of Westminster Abbey by Henry VII to the present-day problems of upkeep and organisation.