Complex sentence: In 1929 Mead and Fortune visited Manus, now the northern-most province of Papua New Guinea, reaching there by boat from Rabaul after a stay there which she amply describes in her autobiography and which is mentioned in her 1984 biography by Jane Howard.
Split into simpler sentences: In 1929 Mead and Fortune visited Manus, now the northern-most province of Papua New Guinea, travelling there by boat from Rabaul. She amply describes her stay there in her autobiography and it is mentioned in her 1984 biography by Jane Howard.