pass the enemy’s lines
...Thoreau's Journal: 19-Jun-1852
It requires considerable skill in crossing a country to avoid the houses and too cultivated parts,—somewhat of the engineer’s or gunner’s skill, —so as to pass a house, if you must go near it through high grass, —pass the enemy’s lines where houses are thick, —as to make a hill or wood screen you, —to shut every window with an apple tree. For that route which most avoids the houses is not only the one in which you will be least molested, but it is by far the most agreeable. Saw the handsomest large maple west of this hill that I ever saw. We crawled through the end of a swamp on our bellies, the bushes were so thick, to screen us from a house forty rods off whose windows completely commanded the open ground, leaping some broad ditches, and when we emerged into the grass ground, some apple trees near the house beautifully screened us. It is rare that you cannot avoid a grain-field or piece of English mowing by skirting a corn-field or nursery near by, but if you must go through high grass, then step lightly and in each other’s tracks.