This great island, or rather continent, is being fast interlaced with lines of telegraph. Electric communication has been opened between Adelaide, South Australia, and Melbourne, and rapid progress is now being made with several other lines. " The South Australian" says the whole of the instruments ordered for the South Australian Telegraph stations have now arrived from America, and workmen are busily engaged under Mr. Todd's superintendence, in preparing them for use. The instrument is Morse's, mounted on marble instead of wood, which is better suited to this climate. Chest@r's patent battery (an improvement upon Smee's) will be, in most cases, employed to generate the galvanic current.