452 GEOLOGICAL FORMATIONS. 



and come upon long tracts of gneiss with hornblende. The 

 gneiss is often striated, all the striae looking one way — sometimes 

 north and south, and at other times east and west. These rocks 

 look as if a stratified rock had been nearly melted, and the strata 

 fused together by the heat. From these striated rocks have 

 shot up great rounded masses of granite or syenite, whose smooth 

 sides and crowns contain scarcely any trees, and are probably 

 from three to four thousand feet above the sea. The elevated 

 plains amo'ng these mountain masses show great patches of fer- 

 ruginous conglomerate, which, when broken, look like yellow 

 haematite with madrepore holes in it: this has made the soil 

 of a red color. 



" On the watershed we have still the rounded granitic hills 

 jutting above the plains (if such they may be called), which are 

 all ups and downs, and furrowed with innumerable running 

 rills, the sources of the Rovuma and Loendi. The highest rock 

 observed with mica schist was at an altitude of three thousand 

 four hundred and forty feet. The same uneven country prevails 

 as we prQceed from the watershed about forty miles down to the 

 lake, and a great deal of quartz in small fragments renders 

 travelling very difficult. Near the lake, and along its eastern 

 shore, we have mica schist and gneiss foliated, with a great deal 

 of hornblende ; but the most remarkable feature of it is that the 

 rocks are all tilted on edge, or slightly inclined to the lake. 

 The active agent in effecting this is not visible. It looks as if 

 a sudden rent had been made, so as to form the lake, and tilt all 

 these rocks nearly over. On the east side of the lower part of 

 the lake we have two ranges of mountains, evidently granitic : 

 the nearer one covered with small trees and lower than the other ; 

 the other jagged and bare, or of the granitic forms. But in all 

 this country no fossil-yielding rock was visible except the gray 

 sandstone referred to at the beginning of this note. The rocks 

 are chiefly the old crystalline forms." 



The soil of the district is good, and water generally abundant. 

 Neither had he suffered particularly in health. If he had been 

 escorted by his Makololo the whole journey would have been a 

 joyous march. The people of Makonde, Makoa and Waiyau 

 had all been generous and kind ; the chiefs had readily rendered 

 him all needed assistance, and seemed to appreciate the lessons 



