Telegraph Company. Telegraph poles were first used on the Great Western Railway in 1843 when the Cooke and Wheatstone telegraph line was extended to Slough. The line had previously used buried cables but that system had proved troublesome with failing insulation. In Britain, the trees used for telegraph poles were either native larch or pine from Sweden and Norway. Poles in early installations were treated with tar, but these were found to last only around seven years. Later poles were treated instead with creosote or copper sulphate for the preservative. Utility poles were first used in the mid-19th century in America with telegraph systems. In 1844, the United States Congress granted Samuel Morse $30,000 to build a 40-mile telegraph line between Baltimore, Maryland and Washington, D.C. Morse began by having a lead-sheathed cable made. After laying seven miles underground, he tested it. He found so many faults with this system that he dug up his cable, stripped off its sheath, bought poles and strung his wires overhead. On February 7, 1844, Morse inserted the following advertisement in the Washington newspaper: "Sealed proposals will be received by the undersigned for furnishing 700 straight and sound chestnut posts with the bark on and of the following dimensions to wit: 'Each post must not be less than eight inches in diameter at the butt and tapering to five or six inches at the top. Six hundred and eighty of said posts to be 24 feet in length, and 20 of them 30 feet in length.'" In some parts of Australia, wooden poles are rapidly destroyed by termites, so metal poles must be used instead and in much of the interior wooden poles are vulnerable to fire. The Oppenheimer pole is a collapsible wrought iron pole in three sections. It is named after Oppenheimer and Company in Germany, but they were mostly manufactured in England under license. They were used on the Australian Overland Telegraph Line built in 1872 which connected the continent north to south directly through the centre and linked to the rest of the world through a submarine cable at Darwin. The Stobie pole was invented in 1924 by James Cyril Stobie of the Adelaide Electric Supply Company and first used in South Terrace, Adelaide. One of the early Bell System lines was the Washington DC–Norfolk line which was, for the most part, square-sawn tapered poles of yellow pine probably treated