  HERMES, a fibre-fed high-resolution (R=85000) echelle spectrograph with good
stability and excellent throughput, is the work-horse instrument of the 1.2-m
Mercator telescope on La Palma. HERMES targets building up time series of
high-quality data of variable stellar phenomena, mainly for asteroseismology
and binary-evolution research. In this paper we present the HERMES project and
discuss the instrument design, performance, and a future upgrade. We also
present some results of the first four years of HERMES observations. We
illustrate the value of small telescopes, equipped with efficient
instrumentation, for high-resolution spectroscopy.
