  The correlation between cosmic shear as measured by the image distortion of
high-redshift galaxies and the number counts of foreground galaxies is
calculated. For a given power spectrum of the cosmic density fluctuations, this
correlation is proportional to the bias factor, which can thus directly be
measured. In addition, this correlation provides a first-order measure of
cosmic shear and is therefore easier to observe than quadratic measures
hitherto proposed. Analytic approximations show that the expected
signal-to-noise ratio of the correlation is large, so that a significant
detection is possible with a moderate amount of data; in particular, it is
predicted that the ongoing ESO Imaging Survey (EIS) will be able to detect this
correlation on scales of $\sim 10'$ at a 3-$\sigma$ level, and at with higher
significance on smaller angular scales.
