May 23, 1859.] DISCOVERIES OF BURTON AND SPEKE. 303 



within the range of the eye.* Its waters are perfectly fresh and 

 peculiarly agreeable to drink, and it abounds in delicious fish, whilst 

 its banks are grazed by red oxen of large size, some of them having 

 stupendously long horns. Oxen are indeed common over nearly 

 all the region examined, for the tsetse fly, the scourge of the more 

 southern African countries, in which Livingstone travelled, is 

 unknown. 



A singular phenomenon of blindness affected for some time both 

 the travellers. Whilst exposed in the arid, hilly coast range, and 

 also in the plateau land, to a fierce and glaring sun, their sight was 

 unaffected ; but on descending into the verdant, well watered, and 

 rich lacustrine expanse of Tanganyika their sight was dimmed, and 

 gradually they became almost blind — their recovery being slow and 

 imperfect. It was this calamity alone which diminished the number 

 of astronomical observations made by Captain Speke, who lost no op- 

 portunity of fixing the latitude and longitude of numerous positions. 



When returned to their chief central station in Unyanyembe, 

 Speke, thriving upon hard field work, left his invalid companion in 

 order to reach the great lake Nyanza, the position of which had 

 been pointed out to him by the Arabs, who asserted that it was 

 much longer and larger than Tanganyika, from which it is separated 

 by about 200 miles. In this journey Captain Speke, accompanied 

 by his faithful Beloochees, passed through the district where the 

 chief iron works of the country are carried on ; the native black- 

 smiths smelting the ore with charcoal. 



The great lake Nyanza was found to occupy the position assigned 

 to it by the Arabs, and the E. longitude being very nearly that 

 of Kaze, viz., 32° 47',t its southern end was fixed at 2" 30' S. 

 lat. Ascending a hill and looking northwards, the enterprising 



* Since this Address was delivered, the British Muse am has acquired a curious, large, 

 old Portuguese MS. map of the world, on the Mercator's projection, made by 

 Antonio Sances, in 1623, which shows how much general knowledge of the interior of 

 Africa was possessed at that period by the Portuguese. On this vellum map, the author 

 distinctly places one large body of water in the centre of Africa, and in the parallel of 

 Zanzibar. Although all the details are inaccurate, and he makes the Congo flow out 

 of this lake to the West, and another river (representing probably the Zambesi), which is 

 called R. de St. Yurzes, from the same to the S.E., still the general notion of great internal 

 waters is there put forth. 



Chevalier Pertz has recently discovered in an old MS. in the Royal Library at Berlin 

 that, even in the year 1291, two Genoese navigators, Teodosio Doria and Ugolino Vivaldi, 

 sailed for a certain distance down the West Coast of Africa. Their ships were called Sanf 

 Antonio and Allegranza, and the last- mentioned name has, indeed, remained attached to 

 the most northern of the Canary Islands. It has been en'oneously stated in some journals 

 that these Genoese navigators sailed roi\nd the Cape of Good Hope. — June 20, 1859. 



•f Lunar observations were made at this station. 



