In 1871 Yablochkov was appointed director of the telegraph lines between Moscow and Kursk, a position he resigned in 1875 to devote himself to research on arc lamps. In 1876 he settled in Paris, and late in that year he completed work on his candles, which consisted of two parallel carbon rods separated by a nonconducting clay partition that gradually vaporized as the carbons burned away. For a few years his system was widely used for street lighting in European cities, but it was gradually superseded by incandescent lighting. Yablochkov contributed various other electrical developments but died in poverty.