  Gravitational lensing by large-scale structure induces weak coherent
alignments in the shapes of background galaxies. Here we present evidence for
the detection of this `cosmic shear' at the 3.4 sigma significance level with
the William Herschel Telescope. Analysis and removal of notable systematic
effects, such as shear induced by telescope optics and smearing by tracking and
seeing, are conducted in order to recover the physical weak shear signal.
Positive results for shear recovery on realistic simulated data are presented,
enhancing confidence in the measurement method. The detection of cosmic shear
is statistically characterised, and its cosmological significance is discussed.
