  We describe the problems met using the telescopes of Merate Observatory, the
branch of Brera Astronomical Observatory. From the point of view of the data
analysis, we discuss how to introduce a satisfactory correction of the variable
extinction coefficient, giving also some examples. We also measured the sky
brightness, obtaining $V$=18.2 mag/arcsec$^2$. The light pollution is
responsible for such a bright background and we present pictures showing its
effects. We are limiting it trying to persuade public administrations to reduce
the light scattered toward the sky by using cutoff lamps and putting out
commercial searchlights. The need of a law which safeguards astronomical
activities is stressed.
