  New GMRT observations of the five-component pulsar B1857--26 provide detailed
insight into its pulse-sequence modulation phenomena for the first time. The
outer conal components exhibit a 7.4-rotation-period, longitude-stationary
modulation. Several lines of evidence indicate a carousel circulation time
$\P3hat$ of about 147 stellar rotations, characteristic of a pattern with 20
beamlets. The pulsar nulls some 20% of the time, usually for only a single
pulse, and these nulls show no discernible order or periodicity. Finally, the
pulsar's polarization-angle traverse raises interesting issues: if most of its
emission is comprised of a single polarization mode, the full traverse exceeds
180\degr; or if both polarization modes are present, then the leading and the
trailing halves of the profiles exhibit two different modes. In either case the
rotating vector model fails to fit the polarization-angle traverse of the core
component.
