  The problem of reconstruction of the 3D velocities of clusters of galaxies
from the redshift distribution of galaxies of the cluster is formulated. Though
numerical simulations show the impossibility of direct use of Ambartsumian's
formula derived for the stellar systems because of the small number of objects
in the clusters, an additional physical assumption on the form of the searched
velocity distribution can lead to the possibility of obtaining the transverse
velocity of the cluster. The accuracy of the proposed reconstruction procedure
is estimated.
