After the preliminary lines have been run, the engineer-in-chief takes up the different maps and lays down a new line, sometimes coinciding with that surveyed, and sometimes quite different. The parties then go back into the field and stake out this new line, called the "approximate location," upon which the curves are all run in. In difficult country the line may be run over even a third or fourth time; or in an easy country, the "preliminary" surveys may be all that is wanted. The life of an engineer, while making surveys, is not an easy one. His duties require the physical strength of a drayman and the mental accuracy of a professor, both exerted at the same time, and during heat and cold, rain and shine. An engineer, once on a time, standing behind his instrument, was surrounded by a crowd of natives, anxious to know all about it. He explained his processes, using many learned words, and flattered himself that he had made a deep impression upon his hearers. At last, one old woman spoke up, with an expression of great contempt on her face, "Wall! If I knowed as much as you do, I'd quit ingineerin' and keep a grocery!" A large part of the financial difficulties of our railways results from not taking time enough to properly locate the line. It must be remembered that a cheaply constructed line can be rebuilt, but with a badly located line nothing can be done except to abandon it entirely. [Illustration: Royal Gorge Hanging Bridge, Denver and Rio Grande, Colorado.] It is well therefore to consider carefully what is the true problem of location. It is so to place and build a line of railway that it shall get the greatest amount of business out of the country through which it passes, and at the same time be able to do that business at the least cost, including both expenses of operating and the fixed charges on the capital invested. The mere statement of this problem shows that it is not an easy one. Its solution is different in a new and unsettled country from that in an old-settled region. In the new country, the shortest, cheapest, and straightest line possible, consistent with the easiest gradients that the topography of the land will allow, is the best. The towns will spring up after the road is built, and will be built on its line, and generally at the places where stations have been fixed. [Illustration: Veta Pass, Colorado.]