  New measurements of galaxy clustering and background radiations provide
improved constraints on the isotropy and homogeneity of the Universe on large
scales. In particular, the angular distribution of radio sources and the X-Ray
Background probe density fluctuations on scales intermediate between those
explored by galaxy surveys and the Cosmic Microwave Background experiments. On
a scale of $\sim 100 \Mpc$ the rms density fluctuations are at the level of
$\sim 10%$ and on scales larger than $300 \Mpc$ the distribution of both mass
and luminous sources safely satisfies the `Cosmological Principle' of isotropy
and homogeneity. The transition with scale from clumpiness to homogeneity can
be phrased in terms of the fractal dimension of the galaxy and mass
distributions.
