Before revision: Cobalt ray-tracing, high-end coffee tamper Manual or powered tampers compact gravel before laying a concrete or brick patio or walkway so that the underlying gravel layer does not settle over time, or compress the fill in a utility trench as seen in the illustration.
After revision: A fancy coffee tamper Manual or powered tampers compact gravel before laying a concrete or brick patio or walkway so that the underlying gravel layer does not settle over time, or compress the fill in a utility trench as seen in the illustration.