David Livingstone your own eye only, ... Doubtful if I live to see you again ..." Henry Morton Stanley had been sent to find him by the "New York Herald" newspaper in 1869. He found Livingstone in the town of Ujiji on the shores of Lake Tanganyika on 10 November 1871, greeting him with the now famous words "Dr Livingstone, I presume?" Livingstone responded, "Yes", and then "I feel thankful that I am here to welcome you." These famous words may have been a fabrication, as Stanley later tore out the pages of this encounter in his diary. Even Livingstone's account of
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