Find number abcIf ab29c + a01cb = 12bcb7 find number abc. Multiple solutions may exist.
Correct answers: 23
The first user who solved this task is Djordje Timotijevic.
Mont Cenis Tunnel openedIn 1871, the Mont Cenis Tunnel opened, the world's first important mountain tunnel. The two track railway tunnel through the Alps under Mont Cenis, united Savoy (north of the mountains) through Switzerland with the rest of Italy to the south. It was 8 miles long, double any previous tunnel's length. Work began in 1857. In 1861, after three years of tedious hand-boring eight inches a day into the Alpine rock face, its builder, French engineer Germain Sommeiller, introduced industrial-scale pneumatics in tunnel digging for the first time. Workers tunnelling from each side met halfway on 26 Dec 1870. The tunnel was inaugurated with the passage of 22 carriages in 20 minutes. Regular train service began 16 Oct 1871. Mail was sent by the tunnel beginning 5 Jan 1872, saving 24 hours from the overland route.*«[Image top: Mont Cenis Tunnel entrance arch; bottom: Sommeiller Boring Machines.]