It was such a gradual movement that he discovered it only through noticing that a black mark that had been near him five minutes ago was now at the other side of the circumference.
This little group had in its advance dragged inward, so to speak, the circumference of the now almost complete circle of people, and a number of dim black figures followed it at discreet distances.
There are no more uses of "circumference" in the book.
Show samples from other sources
He walked quickly around its entire circumference, running his left hand along the wall as he did so.
James Dashner -- The Scorch Trials
In order to ensure that my claim would not be overlooked, I felt obliged to make a property mark on stones, clumps of moss, and patches of vegetation at intervals of not more than fifteen feet around the circumference of my claim.