8KET0H OP AFRICAN DISCOVERT. 
609 
a thousand milos in an easterly direction, and terminated 
in a lako or swamp; others supported the opinion that its 
waters wore lost in tho arid sands of the Desert; wliilo the 
Congo was said by many to bo its outlet. Major Laing, by 
ascertaining tho sourco of tho Niger to bo not more than 
sixteen hundred feet above tho level of tho sea, proved that 
•t could not flow into tho Nilo ; and Denham and Clappei- 
ton demonstrated that it did not, as had been supposed, 
discharge itself into tho Lake of Bomou. 
Richard and John Lander, in 1830, under tho auspices 
of tho British Government, solved tho long-disputod problem 
of tho courso of tho Niger by sailing down on its waters 
from Boussa to tho ocean, where it was found to terminate 
in what was called tho Nun, or First Brass River, from tho 
negro town of Brass situated on its banks. 
An expedition under tho auspices of tho British Govern- 
ment, and headed by Dr. Henry Barth, attended by Dr. 
Overborg and Mr. James Richardson, was sent out in 1849 
to prosccuto discoveries in Northern Central Africa. Their 
travols and researches into tho history and present btato of 
tho interior tribes woro continued till 1855, and their results 
havo recently boon published by Dr. Barth. Dr. Overborg 
died in 1854, and was buried on tho shores of Lako Tchad 
or Tsad. Mr. Richardson also fell a victim to tho climate 
before tho close of tho expedition. 
Dr. Barth visited tho countries of Bornou, Kanom, Man- 
dara, Bagirmi, and others previously explored by Denham 
and Clapporton, and carried his researches much farther, 
reaching tho eighth dogroo of north latitude. His volume* 
oontain much curious and minuto information. 
The following extract from the preface gives a summary 
of his travels : 
“Extending over a tract of country of twenty-four degrees 
from north to south, and twenty degrees from east to west, is 
