Open-air Preacher Dr. David Livingstone (1813-1873), was a curious combination of Scottish missionary, doctor, explorer, scientist and anti-slavery activist. He spent 30 years in Africa, exploring almost a third of the continent, from its southern tip almost to the equator. ―‘‘I am a missionary, heart and soul,’’ wrote Livingstone. ―‘‘God had an only Son, and He was a missionary and a physician. A poor, poor imitation of Him I am, or wish to be. In this service I hope to live; in it I wish to die.’’ From the moment of his landing on African soil, Livingstone is haunted, night and day, by the visions that beckon and the voices that call from out of the undiscovered. For his poor wife’s sake he tries hard, and tries repeatedly, to settle down to the life of an ordinary mission station. But it is impossible.