May 28, I860.] DISCOVERIES OF BURTON AND SPEKE. 179 



variation is greater on shore than at sea. There are other distract- 

 ing causes, well known to observers, which I need not dwell upon 

 here, having already said enough to show that we cannot rely for 

 a moment on the recorded differential altitude of 1C6 feet between 

 the two lakes. All that we are justified in saj^ing at the present 

 moment is that the three lakes, Tanganyika, Nyassa, and Shirwa, 

 appear to be of about the same level, and that it is quite possible 

 the Tanganyika may be the highest of them all. If it be so, and if 

 the Tanganyika be connected (it may or may not be through a 

 chain of small lakes) with the Nyassa, we should have an imme- 

 diate solution of all our difficulties. The surplus waters would be 

 accounted for, and the non-variation of the height of the Shire 

 river would also be accounted for, because the rains, as they fol- 

 lowed the course of the sun, would never entirely leave the lake 

 district during any part of the year. It is a district that would 

 extend with more or less intermission in a long meridional strip 

 of no less than 13° of latitude, beginning with lat. s. 1C°, and 

 ending with lat. s. 3°. 



Far be it from me to press forward this solution in an undue 

 manner. African geographers have too much cause to distrust 

 geographical speculations ; but I wish clearly to point out both the 

 magnitude of the hydrological difficulties which embarrass us, and 

 also the wide limits within which our speculations are obliged, for 

 the present, to rove, in the absence of a few fundamental facts. 



Captain Speke has again set sail for Africa. He has started, accom- 

 panied by our associate Captain Grant, under fair auspices again, and 

 bound for the discovery of the sources of the Nile. This Society 

 has abundant reason to acknowledge the liberal spirit in whicli 

 Her Majesty's Government has acted in supporting this expedition. 

 Captain Speke's instructions are to make the best of his way to the 

 point whence he before turned back, at the southern end of the 

 lake Nyanza, and thence to explore to its northern extremity, seeing 

 whether or no it has a northern outlet. If there should be no 

 connection between the Nyanza and the Nile, he is to use the best 

 of his judgment in prosecuting his search to the sources of the latter, 

 and finally he is to endeavour to reach Gondokoro, the missionary 

 settlement formerly occupied by Knoblecher, and stated to be in 

 N. lat. 4° 25'. 



We are rejoiced to say that Captain Speke is not the only traveller 

 on the Zanzibar coast. Dr. A. Eoscher, a native of Hamburg, pro- 

 ceeded to Zanzibar in 1858, and in 1859 travelled along the coast 

 as far as Kilwa, and explored the lower course of the Lufiji. In a 



