  We study the spectrum of confining strings in SU(3) pure gauge theory, by
means of lattice Monte Carlo simulations, using torelon operators in different
representations of the gauge group. Our results provide direct evidence that
the string spectrum is according to predictions based on $n$-ality. Torelon
correlations in the rank-2 symmetric channel appear to be well reproduced by a
two-exponential picture, in which the lowest state is given by the fundamental
string $\sigma_1=\sigma$, the heavier string state is such that the ratio
$\sigma_2/\sigma_1$ is approximately given by the Casimir ratio $C_{\rm
sym}/C_{\rm f} = 5/2$, and the torelon has a much smaller overlap with the
lighter fundamental string state.
