stream from the lake flowed
north to the Congo and another south to the Zambesi; but for years past
there has been no connection between the lake and the Congo. He sought
in vain, like many explorers after him, for the outlet to Lake
Tanganyika. The mystery was not solved till, more than twenty years
after, Burton discovered the lake; the solution came when the explorer
Thomson and Missionary Hore found the waters of Tanganyika pouring in a
perfect torrent down the valley of the Lukuga to the Congo. The
explanation of the strange phenomenon is that for a series of years the
evaporation exceeds the water receipts, the level of the lake steadily
falls, and the valley of the Lukuga becomes choked with grass; then a
period follows when the water receipts exceed the evaporation, and the
waters rise, burst through the barriers of vegetation in the Lukuga, and
are carried to the Congo once more.

It was his second and third journeys that established Livingstone's fame
as a great explorer. In those journeys (1853-56) his routes were from
the Upper Zambesi to Loanda in Portuguese West Africa, and then from
Loanda to the mouth of the Zambesi, nearly twelve thousand miles of
travel. The third journey was the first crossing of the continent; and
while traversing the wide savannas of the uplands and revealing the
Zambesi, the fourth largest river of Africa, from source to delta, he
was able to verify one of the most brilliant generalizations ever made
by a geologist. Sir Roderick Murchison, President of the Royal
Geographical Society, in 1852, deducing his conclusions from the very
fragmentary and imperfect knowledge of Africa then extant, evolved his
striking hypothesis as to the physical conformation of the continent,
which has been briefly mentioned above and is the accepted fact of
to-day. Livingstone was able to prove the accuracy of this hypothesis,
and he dedicated his "Missionary Travels" to its distinguished author.

The Makalolo chief, Sekeletu, on the Zambesi River, supplied Livingstone
with men, ivory, and trading commissions, that helped the humble and
unknown white man, lacking all financial resources except his slender
salary, to make the two great journeys which kindled the world's
interest and led to the wonderful achievements of our generation. In
this noteworthy incident we see the human agencies through which Africa
will attain the full stature allotted to her. The Caucasian and the
Negro each has his onerous pa