  Anisotropies in the temperature of the cosmic microwave background have been
detected on a range of scales by several different experiments. These
anisotropies reflect the primordial spectrum of metric perturbations in the
early universe. In principle, the largest barrier to a clean interpretation of
the experimental results is contamination by foreground sources. We address
this issue by projecting out likely sources of foreground contamination {}from
seven separate small-angle and medium-angle experiments. We then calculate
likelihood functions for models with adiabatic perturbations, first for the
amplitude of the spectrum while constraining the spectral index to be $n=1$,
and then jointly for the amplitude and spectrum of the fluctuations. All of the
experiments are so far consistent with the simplest inflationary models; for
$n=1$ the experiments' combined best-fit quadrupole amplitude is $Q_{\rm
rms-ps}= 18^{+3}_{-1} \,\,\mu K$, in excellent agreement with the COBE two-year
data. In ($Q_{\rm rms-ps}$, n) space, the allowed region incorporating
intermediate and small-scale experiments is substantially more constrained than
{}from COBE alone. We briefly discuss the expected improvement in the data in
the near future and corresponding constraints on cosmological models.
