What he really saw was the chain of the Sesse Islands extending far out into the lake. His book was scarcely off the press when the letters describing Stanley's boat journeys around the shores of Victoria Nyanza began to be published in London and New York; and the foolish fellow was compelled to recall all the copies of his book that had not passed beyond his reach, and eliminate the statements that made him so ridiculous. Fortunately, there are not many explorers of this stripe. All who watched the progress of African discovery were constantly reminded that geographical progress is usually made only by slow and painful steps. They saw an explorer emerge from the unknown with his notebooks and route maps replete with most interesting facts for the student and the cartographer. Then another explorer would 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.