Friends or Foemen Yesterday

From James H. Knight-Adkin’s “No Man’s Land”:

What are the bounds of No Man’s Land?
You can see them clearly on either hand,
A mound of rag-bags gray in the sun,
Or a furrow of brown where the earthworks run
From the eastern hills to the western sea,
Through field or forest o’er river and lea;
No man may pass them, but aim you well
And Death rides across on the bullet or shell.