Green Was the Earth on the Seventh Day, by Thor Heyerdahl (Abacus, £7.99 in UK)

Thor Heyerdahl won fame half a century ago with his book Kon-Tiki, describing a voyage on a raft across the Pacific with a few…

Thor Heyerdahl won fame half a century ago with his book Kon-Tiki, describing a voyage on a raft across the Pacific with a few companions; his later books, including Aku- aku and The Ra Expeditions, were highly successful but less convincing, and had the aura of being public stunts. He was trained as a biologist before turning to archaeology, and this autobiographical volume harks back to the 1930s when he and his young wife journeyed to the Pacific island of Fatu-Hiva, in search of the elusive Green Paradise.

Predictably, they soon tired of it, but two things ignited in Heyerdahl's mind: the idea which eventually took shape in the Kon-Tiki voyage, and a passionate preservationism. This is the real, private, committed Heyerdahl, not the stunt-man of his later voyages.