Extra letters in two sets of across clues give PALINDROMIC/ UNIQUE PRIME, (describing each member of a series beginning 3, (x =) 11, (y =) 101, 1,111,111,111,111,111,111 …). Further extra letters spell THE NUMBER OF/ THIS EDITION (of CAM). Unjumbling the sequences removed from the three remaining clues gives BI/NAR/Y FIVE, ie 101, the number of MENDELEVIUM (on the Periodic Table), DISNEY’S DOGS (Dalmatians), HAYDN’S CLOCK (Symphony) and ORWELL’S ROOM (in Nineteen Eighty-Four).

Winner: Andrew Mackay (Trinity 1970) Runners-up: Tony Marshall (St Catharine’s 1961) and John Widger (St John’s 1963)