double lines of, [102], [110], [123].
exterior lines of, [102].
fronts of, [92], [330], [338].
in mountainous countries, maxims on, [163].
interior lines of, [102].
line of, how protected, [132].
lines of, converging and divergent, [118].
lines of, how established, [114].
lines of, how influenced, [119].