When Duncan Wall fell in love with the circus, he fell hard. (Many times.) After undergoing rigorous training – and theoretical study – at at France’s École Nationale des Arts du Cirque, he went on to direct a clown-theatre company and then to teach at Canada’s national circus school in Montreal. His new book “The Ordinary Acrobat: A Journey into the Wondrous World of the Circus Past and Present” relays his experiences alongside a history of the art form – from red-and-yellow stripes to contemporary acts like Cirque Du Soleil. He gives Brendan a crash course, with the greatest of ease.