In quite recent days, however, deserts as Frontiers have lost the greater part both of their terror and their strength. Like the loftiest mountains, like the stormiest oceans, they have yielded to the all-conquering influence of steam. When Skobeleff advanced to the extirpation of the Tekke Turkomans at Geok Tepe in 1881, he laid a light railway behind him. As the English troops moved up the Nile to the recovery of Khartoum in 1898, the steel rails kept pace with their advance. It was to the desert line, and not to the actual collision at Omdurman, that the Khalifa owed his destruction. The Turkish railways to Syria, if protracted, would soon deprive Egypt of the security on her eastern border which Napoleon described. Given a level desert with a sound foundation, a railroad becomes the easiest of constructions, and built by competent engineers, can be pushed forward in war time at the rate of three miles a day. Similarly it is the aid of railways that has enabled the United States of America to make so light of the great deserts that stretch eastwards from the Rocky Mountains. There are few desert Frontiers in the world that now remain intact. If occasion arose, the doom of the survivors would probably be sealed. It is a question, not of mechanics, but of water and fuel. On the other hand, a ghost of the idea may be said to survive in the still existing preference of uninhabited or thinly peopled tracts as Frontiers over areas of crowded occupation.
I turn to the consideration of the third type of Natural Frontier, namely, mountains. We have already seen that mountains were the earliest of the barriers
- In the Soudan campaign of 1898, 5,300 yards of railway were surveyed, embanked, and laid in a single day.