Radio timing observations of the high-magnetic-field pulsar PSR J1718 - 3718 have shown that it suffered a large glitch with \Delta \nu _ { g } / \nu = ( 33.25 \pm 0.01 ) \times 10 ^ { -6 } between 2007 September ( MJD 54336 ) and 2009 January ( MJD 54855 ) .
This is the largest pulsar glitch ever observed .
As is common , there was a small increase in braking torque at the time of the glitch but , unlike all other pulsars , the braking torque has continued to increase over the two years since the glitch .
Polarization observations show that the mean pulse profile has about 30 % linear polarization with a smooth change of position angle through the pulse and give a rotation measure of -160 \pm 22 rad m ^ { -2 } .
There was no detectable change in pulse profile at the time of the glitch .
The timing observations also gave an improved dispersion measure of 371.1 \pm 1.7 cm ^ { -3 } pc .