Ravenels Road Primer for School Children

rements of a good road as to distance, nature of soil, and ascent and descent, or grade. There is an old axiom, that a straight line is the shortest distance between any two points, so that, all other things being considered satisfactory, the most direct line is the most desirable. In a level country the alignment is easy: it is simply running a line connecting the initial point and the objective points. But when great irregularities of surface interfere, it is as difficult as it is important; for the grade line ? the rise and fall ? must be kept in mindall the time, and it takes an instrument or the eye of an experienced engineer to determine this. Another important item of cost to be considered is the equalizing of the cuts through the hills, and the adjacent fills, or embankments, across the hollows. When the earth taken out of a cut is just sufficient to make the embankment, it is moved only once, as it is hauled from the cut to the fill; but if the cut is less than the embankment, more earth has to be hauled to make that embankment; and if the cut is greater than the embankment, the surplus or extra earth must be hauled off. So it is often the case, that a deviation from the straightest and shortest course is necessary to overcome or avoid such serious obstructions and barriers as hills, hollows, streams, swamps, or other undesirable conditions in road-building and maintenance. In other words, the road should be as straight as possible; but ...