214   Life and Letters of Francis Galton

probably be first confined to London. There would be central offices, and from these bundles of wires would radiate to numerous branch offices; from the branch offices

again wires would pass along the adjacent streets, and supply houses as they passed. The expense of distributing wires in this way could not be extreme, for, if the branch

offices were as numerous as the branch post offices now are, the distance that the wires to each private house would have to traverse would never be great". (p. 32).

The perfect system of house to house telegraphy will probably only be reached when we return to the recorded signal, to the true telegraph, to the written instead of the spoken word. But in a large measure Galton's anticipation of 1849 has been realised. Before, however, the world could express any opinion on the value of his telotype, the "spring-fret " had again seized him. Galton was off for the "misty sweat bath 'neath the line," but this time with a definite end to his travels-the exploration of a little known, tract of Tropical Africa. When and how the idea of a journey of exploration in Africa occurred to Francis Galton we cannot now ascertain ; the reader will remember his boyish admiration for Captain Sayers (see p. 113), which was doubtless not without permanent influence. Oswell, Murray and Livingstone had just reached Lake Ngami, proceeding from the Cape, while ten years earlier Captain (later Sir) James E. Alexander, starting also from the Cape, had twice traversed the country of the Great Namaquas, and travelling almost due east and west along Lat. 23° S. had linked Walfisch Bay with the country of the Damaras of the Hills. North of 23° S. from Walfisch Bay to Lake Ngami, of the land of the Damaras of the Plains and of the Ovampos, but little was known; it was to this land that Galton's attention was ultimately directed. Oswell and Livingstone were" already at work to the north of Lake Ngami, and there seems little doubt that Galton for a considerable time had in mind the linking up of the districts traversed by them with the West Coast. But this was hardly his original project ; that appears to have been to reach Lake Ngami from the Cape and then proceed northward by means of the rivers flowing into that lake'. For this purpose his equipment contained originally two boats which were discarded at the Cape. Galton's friend, Dalyell, was acquainted with Sir Roderick Murchison, at that time President of the Royal Geographical Society; Galton's cousins Charles Darwin and Captain Douglas Galton were

1 Colborne's New Monthly Magazine, November 1850, p. 350.