  This paper reports the results of a survey of Doppler shift oscillations
measured during solar flares in emission lines of S XV and Ca XIX with the
Bragg Crystal Spectrometer (BCS) on Yohkoh. Data from 20 flares that show
oscillatory behavior in the measured Doppler shifts have been fitted to
determine the properties of the oscillations. Results from both BCS channels
show average oscillation periods of 5.5 +/- 2.7 minutes, decay times of 5.0
+/-2.5 minutes, amplitudes of 17.1 +/- 17.0 km/s, and inferred displacements of
1070 +/- 1710 km, where the listed errors are the standard deviations of the
sample means. For some of the flares, intensity fluctuations are also observed.
These lag the Doppler shift oscillations by 1/4 period, strongly suggesting
that the oscillations are standing slow mode waves. The relationship between
the oscillation period and the decay time is consistent with conductive damping
of the oscillations.
