 By 7 November 1857 they had traveled over 600 miles on foot and donkey and they reached Kazeh (Tabora), where they rested and recuperated among Arab slave traders who had a settlement there.In Kazeh Burton became gravely ill and Speke went temporarily blind as they travelled further west.After an arduous journey, the two arrived in Ujiji in February 1858 and became the first Europeans to reach Lake Tanganyika (although Speke was partially blind at this point and could not properly see the lake).