From the Alps to the Adriatic, through Ferrara, Mantova, Parma, Cremona, Pavia and Turin. Those who read Helena Attlee’s recent Lev’s Violin will know something of its historical use, but now the Po is drying up, its irrigation channels green with algal blooms from excessive nitrogen run-off from farmland, and the fertile delta increasingly saline – the sea has seeped 12 kilometres inland. Jones’ account of his journey end-to-end and of those he meets along the way is equally fascinating and chastening.