US Presidency
1910

These are in part due to the flowing of surface soil and decomposed sedimentary rocks upon inclined surfaces of the underlying undecomposed rock and in part by the crushing of structurally weak beds under excessive pressure. These slides occur on one side or the other of the cut through a distance of 4 or 5 miles, and now that their character is understood, allowance has been made in the calculations of yardage for the amount of slides which will have to be removed and the greater slope that will have to be given to the bank in many places in order to prevent their recurrence. Such allowance does not exceed ten millions of yards. Considering that the number of yards removed from this cut on an average of each month through the year is 1,300,000, and that the total remaining to be excavated, including slides, is about 30,000,000 yards, it is seen that this addition to the excavation does not offer any great reason for delay.