Livingstone–Stanley Monument Livingstone–Stanley Monument The Livingstone–Stanley Monument at Mugere in Burundi is 12 km south of the capital Bujumbura, overlooking Lake Tanganyika, and marks a location where explorer and missionary Dr David Livingstone and journalist and explorer Henry Morton Stanley visited and spent two nights on 25–27 November 1871. In French it is referred to as "La Pierre de Livingstone et Stanley". Some Burundians claim the location is where the famous first meeting of Livingstone and Stanley took place, at which the latter uttered the famous words "Dr Livingstone, I presume?". However that meeting actually took place in Ujiji in Tanzania on
19th century in science later in the 19th century by the German mathematician Bernhard Riemann; here no parallel can be found and the angles in a triangle add up to more than 180°. Riemann also developed Riemannian geometry, which unifies and vastly generalizes the three types of geometry. The 19th century saw the beginning of a great deal of abstract algebra. Hermann Grassmann in Germany gave a first version of vector spaces, William Rowan Hamilton in Ireland developed noncommutative algebra. The British mathematician George Boole devised an algebra that soon evolved into what is now called Boolean algebra, in which the only numbers were