  We study the sedimentation of colloidal gels by using a combination of light
scattering, polarimetry and video imaging. The asymptotic concentration
profiles $\varphi(z,t\rightarrow \infty)$ exhibit remarkable scaling
properties: profiles for gels prepared at different initial volume fractions
and particle interactions can be superimposed onto a single master curve by
using suitable reduced variables. We show theoretically that this behavior
stems from a power law dependence of the compressive elastic modulus
\textit{vs} $\varphi$, which we directly test experimentally. The sedimentation
kinetics comprises an initial latency stage, followed by a rapid collapse where
the gel height $h$ decreases at constant velocity, and a final compaction stage
characterized by a stretched exponential relaxation of $h$ towards a plateau.
Analogies and differences with previous works are briefly discussed.
