The Bardoneche entrance is not visible, as it is in the midst of the mountains, far away from any roadway, and 426 feet higher above the level of the sea than the Modane entrance. At Lanslebourg, the road which has, for all the distance from St. Michel, run nearly due east, makes a sudden turn to south-west and continues in this direction to Susa. The course of the tunnel is south-west throughout its entire length. It is consequently parallel or nearly parallel to the Mont Cenis Road, between Lanslebourg and Susa; although, as just stated, they are about 15 miles apart. The following little outline will convey to the reader an idea of the relative positions of tunnel and railway. [Illustration] We have drawn a straight line between Lanslebourg and Susa, solely for representing the general direction of the road; but in reality the road is a cork-screw with fully as constant deviation from the straight line as is exhibited by that useful article of domestic economy, and perhaps we could not find a better manner of illustrating the difference between an ordinary road on the level, and one on or through a mountain passway. If the iron of a cork-screw went straight from where it is fastened to the handle, to its point or extremity, it would measure about three inches, but its convolutions extend it to ten. It is precisely the same with the road between Lanslebourg and Susa. If it were on the plain it would measure about seven miles; but its convolutions, its twists and its turns, its zig-zags, and its _lacets_ convert seven into twenty-five. The length of the tunnel when completed will be 12,220 metres, or 7½ English miles and 242 yards. It consequently exceeds by about 4½ miles, the next longest railway tunnel on the continent of Europe, that of Lanerthe, on the Paris, Lyons and Mediterranean Railway already referred to. The Tunnel of the Alps has a double nationality, it is half, exactly half, French, and exactly half Italian. By the convention of 1856, between the Governments of Sardinia and France, 6,110 metres of perforation and of lining were to be made at the expense of each country, but the whole of the works were to be done by Italy exclusively. They were commenced on each side of the mountain in 1857. For the first 3½ years, that is, until the end of 1860, the process of perforation was performed by manual labour only; in 1861 and 1862 it was partly by manual labour and partly by machinery; since 1862, machinery has been exclusively adopted. The following Table sets forth the progress made on each side since the commencement of the work. THE TUNNEL OF THE ALPS.