  A circle C holds a convex body K if C does not meet the interior of K and if
there does not exist any euclidean displacement which moves C as far as desired
from K, avoiding the interior of K. The purpose of this note is to explore how
small can be a holding circle. In particular it is shown that the diameter of
such a holding circle can be less than the width w of the body but is always
greater than 2w/3.
