  We have used widely spaced in time Hubble Space Telescope images to determine
tangential velocities of features associated with outflows from young stars.
These observations were supplemented by groundbased telescope spectroscopy and
from the resultant radial velocities, space velocities were determined for many
outflows. Numerous new moving features were found and grouped into known and
newly assigned Herbig Haro objects.
  It was found that stellar outflow is highly discontinuous, as frequently is
the case, with long-term gaps of a few hundred years and that these outflow
periods are marked by staccato bursts over periods of about ten years. Although
this has been observed in other regions, the Orion Nebula Cluster presents the
richest display of this property.
  Most of the large scale Herbig Haro objects in the brightest part of the
Orion Nebula appear to originate from a small region northeast of the strong
Orion-S radio and infrared sources. With the possible exception of HH 203, we
are not able to identify specific stellar sources, but do identify candidate
sources for several other bright Herbig Haro objects.
  We find that there are optical features in the BN-KL region that can be
related to the known large scale outflow that originates there. We find
additional evidence for this outflow originating 500 to 1000 years ago.
