sentences:  Portuguese explorer Serpa Pinto examined some of the western tributaries of the river and made measurements of the Victoria Falls in 1878.In 1884 the Scottish-born Plymouth Brethren missionary Frederick Stanley Arnot traveled over the height of land between the watersheds of the Zambezi and the Congo, and identified the source of the Zambezi.He considered that the nearby high and cool Kalene Hill was a particularly suitable place for a mission.