Subterranean Telegraphy

Eutire euocess is olaimed for the onterprise of subterranenu telegraphy in Germany. Tho wires between Berlin and Halle have been in uso for twelve months, and their conducting power has increased, no fault hnving yet been dofcected in the insulation. Tho line Í3 formcd by a cable of Beven thin copper wires twisted together so as to be a single conductor ; they are cased in India-rubber, and laid iu a trenoh which is dug and afterward iilied in by a steam excavator. The trench dug by this machine is nnifoim ; it is ono inetre deip and half a metre wide. The work iu orJinary soil is said to go forward with great expedition, and uuderground wires will soon be laid between all the chief cities.