  Using 172 plates taken with the 40-cm astrograph of the Sternberg
Astronomical Institute (Lomonosov Moscow University) in 1976-1994 and digitized
with the resolution of 2400 dpi, we discovered and studied 275 new variable
stars. We present the list of our new variables with all necessary information
concerning their brightness variations. As in our earlier studies, the new
discoveries show a rather large number of high-amplitude Delta Scuti variables,
predicting that many stars of this type remain not detected in the whole sky.
We also performed automated classification of the newly discovered variable
stars based on the Random Forest algorithm. The results of the automated
classification were compared to traditional classification and showed that
automated classification was possible even with noisy photographic data.
However, further improvement of automated techniques is needed, which is
especially important having in mind the very large numbers of new discoveries
expected from all-sky surveys.
