  In this paper we evaluate the spectrum of the pregalactic density field on
scales $1h^{-1}Mpc < r < 100h^{-1}$Mpc from a variety of astronomical data. APM
data on $w(\theta)$ in six narrow magnitude is used, after correcting to
possible evolutionary effects, to constrain the spectrum of galaxy clustering
on scales $10h^{-1}Mpc < r < 50-100h^{-1}Mpc$. Fitting power spectra of CDM
models to the data at all depths requires $\Omega h=0.2$ if the primordial
index $n=1$ and $\Omega h=0.3$ if the spectrum is tilted with $n=0.7$. Then we
compare the peculiar velocity field predicted by the APM spectrum of galaxy
(light) distribution with the actual velocity data. The two fields are
consistent and the comparison suggests that the bias factor is scale
independent with $\Omega^{0.6}/b\simeq$(0.2-0.3). The next dataset used comes
from the cluster correlation data. We calculate in detail the amplification of
the cluster correlation function due to gravitational clustering and use the
data on both the slope of the cluster correlation function and its
amplitude-richness dependence. Cluster masses are normalized using the Coma
cluster. We find that CDM models are hard to reconcile with all the three
datasets: APM data on $w(\theta)$, the data on cluster correlation function,
and the data on the latter's amplitude-richness dependence. We show that the
data on the amplitude-richness dependence can be used directly to obtain the
spectrum of the pregalactic density field. Applying the method to the data, we
recover the density field on scales between 5 and 25$h^{-1}$Mpc whose slope is
in good agreement with the APM data on the same scales. Requiring the two
amplitudes to be the same, fixes the value of $\Omega$ to be 0.3 in agreement
with observations of the dynamics of the Coma cluster. Finally we use the data
