Tom Reade and Harry Hazelton, on the other hand, had felt no call to military glory. For their work in life they longed to become part of the great constructive force wielded by modern civil engineers. During the latter part of their high school work they had studied hard with ambition to become surveyors and civil engineers. In their school vacations they had sought training and experience in the offices of an engineering firm in their home town of Gridley. After being graduated from the Gridley High School, Tom and Harry had done more work in the same offices. Then, in a sudden desire for advancement, and possessed by the longing for a wider field of endeavor, Tom Reade and Harry Hazelton had secured positions as "cub engineers" on the construction work that was being done to rush a new railway, system over the Rocky Mountains in Colorado. The stern, hard work that lay before them, the many adventures in a rough wilderness, and the chain of circumstances that at last placed Tom Reade in charge of the railroad building, with Harry as first assistant engineer, are all told in the first volume of this present series, "_The Young Engineers In Colorado_." That great feat finished satisfactorily, the ambition of our young engineers led them further afield, as told in "_The Young Engineers in Arizona_." A great, man-killing quicksand had to be filled in and effectively stopped from shifting. Reade & Hazelton undertook the task. Incidentally Tom came into serious, dangerous conflict with gamblers and other human birds-of-prey, who had heretofore fattened on the earnings of the railway laborers. It was a tremendously exciting time that the young engineers had in Arizona, but they at last got away with their lives and were at the same time immensely successful in their undertaking. In "_The Young Engineers In Nevada_" we found our young friends under changed conditions. While at work in Colorado and in Arizona Tom and Harry had studied the occurrence of precious ores, and also the methods of assaying and extracting ores. Having their time wholly to themselves after finishing in Arizona the dauntless young pair went to Nevada, there to study mining at first hand. In time they located a mining claim, though there were other claimants, and around this latter fact hung an extremely exciting story. Both young engineers nearly lost their lives in Nevada, and met with many strenuous situations. Their sole idea in pushing their mine forward to success was that the money so earned would enable them to further their greatest ambition; they longed to have their own engineering offices. In the end, their mine, which the young engineers had named "The Ambition," proved a success. Thereupon they left their mining partner, Jim Ferrers, in charge and went east to open their offices.