Peter had a compass, but he didn't need to use it, for he had a kind of 'feel' for landscape, a special sense which is born in savages and can only be acquired after long experience by the white man.

I believe he could smell where the north lay.

He had settled roughly which part of the line he would try, merely because of its nearness to the enemy.

But he might see reason to vary this, and as he moved he began to think that the safest place was where the shelling was hottest.

He didn't like the notion, but it sounded sense.
Suddenly he began to puzzle over queer things in the ground, and, as he had never seen big guns before, it took him a moment to fix them.
Presently one went off at his elbow with a roar like the Last Day.
These were Austrian howitzers--nothing over eight-inch, I fancy, but to Peter they looked like leviathans.