It was with fear and trembling that one looked to see whether all had been saved or only part, but with satisfaction and thankfulness I have subsequently discovered that his men preserved every single line, besides his maps, which now come to light for the first time. Thus much on the material of the diaries: it remains to say a few words on the Map which accompanies these journals. It has been compiled from Dr. Livingstone's original drawings and note-books, with the corrections and additions he made from time to time as the work of exploration progressed, and the details of physical geography became clearer to him. The compiler, Mr. John Bolton[1], implicitly following the original outline of the drawing as far as possible, has honestly endeavoured to give such a rendering of the entire work, as the Doctor would have done had he lived to return home, and superintend the construction; and I take this opportunity of expressing my sincere gratification that Mr. Bolton's rare technical skill, scientific knowledge, and unwearying labour have been available for the purpose. Amongst almost the last words that Livingstone wrote, I find an unfinished letter to myself, in which he gives me very clear and explicit directions concerning the geographical notes he had previously sent home, and I am but carrying out the sacred duty which is attached to a last wish when I call attention to the fact, that he particularly desired in this letter that _no positions gathered from his observations for latitude and longitude, nor for the levels of the Lakes, &c., should be considered correct till Sir Thomas Maclear had examined them_. The position of Casembe's town, and of a point near Pambette at the S.E., and of Lake Liemba (Tanganyika), have been computed and corrected by Sir T. Maclear and Dr. Mann. The observations for latitude were taken at short intervals, and where it has been possible to test them they have been found very correct, but I repeat that until the imprimatur of his old friend at the Cape of Good Hope stands over the whole of Livingstone's work, the map must be accepted as open to further corrections.