ould enter the same
region, discover facts that had escaped the notice of the pioneer,
correct blunders his predecessor had made and perpetrate blunders of his
own; so explorer followed explorer, each adding something to
geographical knowledge, each correcting earlier misconceptions, till the
total product, well sifted by critical geographers, gave the world a
fair idea of the region explored; but not the best attainable idea, for
scientific knowledge of a region comes only with its detailed
exploration by trained observers, equipped with the best appliances for
use in their special fields of research. This is the advanced stage of
geographical study, which is now being reached in many parts of Africa.
It was Livingstone's task, in 1859, to inform us that there was a great
Lake Nyassa. It was Rhoades's task, in 1897-1901, to make a careful and
accurate survey of its coast-lines, and to sound its depths, so that we
now have an excellent idea of the conformation of the lake bottom.
Between Livingstone and Rhoades came many explorers, each adding
important facts to our knowledge of this great sheet of water nearly
twice as large as New Jersey.

As each explorer came from the wilds, our maps were corrected to conform
with the new information he supplied; and if we should examine the maps
of Africa in school geographies, atlases, and wall maps, from the time
of Livingstone to the present day, we should see that, as relates to
nearly every part of Africa, they have been in a continual state of
transition.

For years our only map of Victoria Nyanza was that which Speke made on
his second journey to the lake, in 1860-62; but Speke saw the great lake
only at one point on its south shore, and along its northwest and north
central coasts. His map, being based very largely upon native
information, was in many respects most incomplete and erroneous.

Then came Stanley's survey of the lake, made in a boat journey around
its coasts, and for years his map supplanted that of Speke. But he was
not able to follow the shore-line in all its intricate details. His
mapping was a great advance upon that of Speke, but it was necessarily
rough and imperfect. He missed entirely the deep indentation of Baumann
Gulf and the southwestern prolongation of the lake, surveyed by Father
Schynse, in 1891. Stanley's map, modified by the partial surveys of
various explorers, is still our mapping of the lake; but if the reader
will watch the maps for the