  This paper presents a measurement of the angular power spectrum of the Cosmic
Microwave Background from l=75 to l=1025 (~10' to 5 degrees) from a combined
analysis of four 150 GHz channels in the BOOMERANG experiment. The spectrum
contains multiple peaks and minima, as predicted by standard
adiabatic-inflationary models in which the primordial plasma undergoes acoustic
oscillations. These results significantly constrain the values of Omega_tot,
Omega_b h^2, Omega_c h^2 and n_s.
