Mary, lived in the same house together only four of the seventeen years of their marriage. When Mary Moffat, Livingstone’s mother-in-law, heard that he had taken her daughter and grandchildren on another dangerous exploring expedition, she wrote him a stinging letter, signed, “I remain yours in great perturbation. M. Moffat.” Unlike his fellow explorers and traveling companions, Livingstone enjoyed relatively good health during his first years in Africa. He traversed the continent for a dozen years