Australia was a relatively early adopter of electrical telegraph technology in the middle of the nineteenth century, despite its low population densities and the difficult conditions sometimes encountered in laying lines. From 1858 onwards, the major capitals were progressively linked, culminating in the addition of Perth in 1877. Australia was linked to the rest of the world for the first time in 1872, through the Overland Telegraph which ran some 3,200 kilometres (2,000 mi) from Adelaide through to Darwin. The network continued to expand in size and sophistication until 1959 and in heavy usage until 1945, after which time telephone usage began to erode public patronage of telegraphy services. The final publicly provided telegraphy service was closed in 1993.