In this paper we evaluate the spectrum of the pregalactic density field on scales 1h \Gamma1 Mpc ! r ! 100h \Gamma1 Mpc from a variety of astronomical data. We start with the APM data on the projected angular correlation function, w(`), in six narrow magnitude bins and check whether interpretation of the w(`) data in terms of the underlying power spectrum can be affected by possible evolutionary effects. This is done by normalizing the the angular correlation function on small scales where the underlying 3-dimensional galaxy correlation function, ¸(r) is known. It allows us to test the various fits to the APM data power spectrum more accurately. We find that for linear scales r ? 10h \Gamma1 Mpc the Baugh and Efstathiou (1993) spectrum of galaxy distribution gives the best fit to the data at all depths. 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. Next..