are nearly 7 miles of tunnels (39 in number), of which 23 are on the ascent from Pistoja, and 16 on the descent to Poretta. The longest is 1⅞ mile, the second longest 1⅝ mile, the length of the others is pretty nearly equal. Nearly one-eighth of what is not tunnel is bridge or viaduct; some of the latter across ravines 300 to 400 feet long, and nearly 180 feet high. They are, in fact, double viaducts, one built on the top of the other, and reminding one of the two tiers of guns of an old-fashioned two-decker. According to the testimony of M. Desbriere, Mr. Fell would have accomplished an equally efficient railway on or through the pass in a couple of years. He would have had no tunnels, unless when, occasionally, he might want to get by a short cut through a projecting ledge of rock or mountain instead of round it, and, as to bridges and viaducts, a twentieth part of those now existing would have amply sufficed him. Before quitting this subject, we would observe that Captain Tyler sets down the difference between the length of a mountain road with gradients of 1 in from 12 to 15 as one-half that of a roadway with gradients of 1 in 40. In practice, however, it will probably be found that the difference will hardly be so great—but there can be no doubt of its not being less than as 3 to 5. Taking the question of working expenses, we know that on the Sœmmering, on the Giovi, and on the Pistoja lines, the weight of the engines is about fifty-five tons, and that on the Sœmmering and the Giovi the cost per train mile is 6s. 2d. _down_ the pass as well as up it, while the average cost on the ordinary portions of the lines is under 3s. a mile; and so oppressive is the working cost of goods trains over the Sœmmering felt to be, and with such uncertainty are the trains, but especially the goods trains, worked over the pass, that before the end of the present year, a railway between Vienna and Trieste will be opened, with a detour of 110 miles, and it is by this roundabout line that the immense and continuously increasing goods traffic between the interior of Austria and its great naval and commercial sea port, will eventually be conveyed to it.