The great difficulties of constructing the Trans-Siberian Railway were mainly due to its abnormal length. Whereas the Americans had only 2,000 miles to cut in creating their line between the Mississippi and the Pacific, the Russians thirty years later had to lay down more than 4,000 miles of rail in order to reach the same ocean from the Ural. Otherwise their difficulties were very much less formidable than those which at times nearly baffled even the ingenuity of the Americans. Happily there are no Rocky Mountains or Sierra Nevada in Siberia to traverse at a great height, but only comparatively low ranges like the Yablonovoi, or ‘Apple-Tree Mountains,’ so-called from their rather dumpy shapes. Then, again, although Siberia is at present not more densely inhabited than was the Far West from 1860 to 1870, it contains no such desolate regions as the plateaus of Utah and Nevada. It may, therefore, be safely affirmed that from the engineering point of view the task was a comparatively easy one, although the line has to pass over an exceedingly varied country after leaving the Ural, and through interminable plains, to reach the undulating regions between the Obi and the Yenissei, where it ascends a chain of hills at an altitude of not less than 2,000 feet on the road from the Yenissei to Irkutsk. On the eastern shore of the Baikal the railway gradually ascends to an altitude of not less than 3,500 feet above the level of the water, whence it descends in rapid zigzag into the valleys of the Ingoda and the Chilka, cuts the abrupt spurs of some very high mountains, and passes into marshlands where, by the way, the engineers have had to overcome their greatest obstruction, mainly due to the unstable condition of the soil. When, therefore, we take into consideration that between the Amur and the Ural there is not a single tunnel, we may safely conclude that, if it were not for its enormous length, this now famous line has not been from the engineering point of view as arduous an undertaking even as have been, for instance, some of the much shorter lines nearer home, across the Alps and the Cevennes.