To the operating heads of the great railroad systems, rebuilding a line is to-day a far more important problem than the building of new routes. The country has grown--grown in wealth, among other things. The causes that demanded the very greatest economy in the building of early railroad lines no longer exist. The hill that the early engineer carefully rounded with his line is now pierced without a second thought. Grades that were once deemed slight are now classed as impossible. The almost infinite development in the operation of the railroad has seen the grade or the curve, not as a slight matter, but as a matter which, however slight in a single instance, becomes in the course of constant operation a heavy operating expense. To-day the operating folk of the big railroads are counting the pennies where they countlessly multiply in these fashions; it is one of the greatest factors in the grinding operation competition between the great railroad systems of the country. It is all quite as it should be. The early builders did the best that they might do with the opportunities that were theirs. They got the railroad through. It developed wealth for itself, as well as for the territory it served; and with that wealth it is enabled in these piping days of peace and plenty to correct the alignment errors of the early builders. Moreover, there are frequent cases where the steady increase of traffic has rendered it necessary for a railroad to parallel its trunks with new lines, quite aside from the consideration of grade and curve. As far back as the early fifties this great work of rebuilding the trunk-line railroads was begun. Certain serious errors in the original alignment of the Baltimore & Ohio Railroad between Baltimore and the Potomac River were corrected, even though at a considerable expense. As time went on, other railroads continued this correction work. It is still being prosecuted east and west of the Mississippi. Ten million dollars, fifty million dollars, looks like a lot of money to the stockholders of any company, when their president tells them that this is to be the cost of this new relief line, this reconstruction, that cut-off; but what is $1,000,000 when it is going to save more than $100,000 a year in the operation of your railroad? It is the big sight of the big situation that the railroads make nowadays at this reconstruction work. Mr. Harriman, with his transcontinentals from the Mississippi watersheds west, was almost the pioneer in this work of wholesale reconstruction. The wholesale operating benefits that have resulted from it in the case of his group of Pacifics have been largely responsible for his preëminence in the railroad world. And yet, once his method was tried, it all seemed simpler than A, B, C.