while building one of the South American railroads it does make us wonder why we should be the ones to reap the benefits of so much that others sowed, doesn't it?" mused the boy's father. "Do you mean to say that ten thousand persons were killed while that railroad was being built?" questioned Stephen, aghast. "They were not all killed," was the reply. "Many of them died of exposure to cold, and many from the effects of the climate. Epidemics swept away hundreds of lives. This particular railroad was one of the mightiest engineering feats the world had seen for in its path lay the Andes Mountains, and there was no escape from either crossing or tunneling them. The great tunnel that pierces them at a height of 15,645 feet above sea level is one of the marvels of science. In various parts of the world there are other such monuments to man's conquest of the opposing forces of nature. Honeycombing the Alps are spiral tunnels that curve round and round like corkscrews inside the mountains, rising slowly to the peaks and making it possible to reach the heights that must be traversed. Among these marvels is the Simplon Tunnel, famous the world over. The road that crosses the Semmering Pass from Trieste to Vienna is another example of what man can do if he must. By means of a series of covered galleries it makes its way through the mountains that stretch like a wall between Italy and Austria. In the early days this territory with its many ravines and almost impassable heights would have been considered too difficult to cross. The railroad over the Brenner Pass between Innsbruck and Botzen penetrates the mountains of the Tyrol by means of twenty-three tunnels." "I learned about the St. Gothard tunnel in school," Steve interrupted eagerly. "Yes, that is yet another of the celebrated ones," his father rejoined. "In fact, there are now so many of these miracles of skilful railroading that we have almost ceased to wonder at them. Railroads thread their way up Mt. Washington, Mt. Rigi, and many another dizzy altitude; to say nothing of the cable-cars and funicular roads that take our breath away when they whirl us to the top of some mountain, either in Europe or in our own land. Man has left scarce a corner of our planet inaccessible, until now, not content with scaling the highest peaks by train, he has progressed still another stage and is flying over them. Thus do the marvels of one age become the commonplace happenings of the next. Our ancestors doubtless thought, when they had accomplished the miracles of their generation, that nothing could surpass them. In the same spirit we regard our aeroplanes and submarines with triumphant pride. But probably the time will come when those who follow us will look back on what we have done and laugh at our attempts just as you laughed when I told you of the first railroad." Stephen was thoughtful for a moment. "It's a great game--living--isn't it, Dad?"