Given an irrational number
$\alpha$
and a positive integer $m$,
the distinct fractional parts of $\alpha, 2\alpha, \cdots, m\alpha$
determine a partition of the interval
$[0,1]$.
Defining $\displaystyle{d_{\alpha}(m)}$ and
$\displaystyle{d'_{\alpha}(m)}$ to be
the maximum and minimum lengths, respectively, of the
subintervals of the
partition corresponding to the integer $m$,
it is shown that the sequence
$\displaystyle{\left(\frac{d_{\alpha}(m)}
{d'_{\alpha}(m)} \right)_{m=1}^{\infty}}$ is
bounded if and only if $\alpha$ is of constant type.
(The proof of this assertion is based on the
continued fraction expansion of irrational numbers.)